/*
- * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2011 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
*
* from: @(#)kern_exec.c 8.1 (Berkeley) 6/10/93
*/
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
#include <machine/reg.h>
#include <sys/param.h>
#include <sys/signal.h>
#include <sys/aio_kern.h>
#include <sys/sysproto.h>
+#if SYSV_SHM
#include <sys/shm_internal.h> /* shmexec() */
+#endif
#include <sys/ubc_internal.h> /* ubc_map() */
+#include <sys/spawn.h>
+#include <sys/spawn_internal.h>
+#include <sys/codesign.h>
+#include <crypto/sha1.h>
-#include <bsm/audit_kernel.h>
+#include <security/audit/audit.h>
+
+#include <ipc/ipc_types.h>
#include <mach/mach_types.h>
+#include <mach/port.h>
#include <mach/task.h>
+#include <mach/task_access.h>
#include <mach/thread_act.h>
#include <mach/vm_map.h>
#include <mach/mach_vm.h>
#include <mach/vm_param.h>
+#include <kern/sched_prim.h> /* thread_wakeup() */
+#include <kern/affinity.h>
+#include <kern/assert.h>
+
+#if CONFIG_MACF
+#include <security/mac.h>
+#include <security/mac_mach_internal.h>
+#endif
+
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
-#include <vm/vm_pager.h>
+#include <vm/vm_protos.h>
#include <vm/vm_kern.h>
-#include <vm/task_working_set.h>
-#include <vm/vm_shared_memory_server.h>
+
+#include <machine/pal_routines.h>
+
+#if CONFIG_DTRACE
+/* Do not include dtrace.h, it redefines kmem_[alloc/free] */
+extern void (*dtrace_fasttrap_exec_ptr)(proc_t);
+extern void (*dtrace_helpers_cleanup)(proc_t);
+extern void dtrace_lazy_dofs_destroy(proc_t);
+
+#include <sys/dtrace_ptss.h>
+#endif
+
+/* support for child creation in exec after vfork */
+thread_t fork_create_child(task_t parent_task, proc_t child_proc, int inherit_memory, int is64bit);
+void vfork_exit(proc_t p, int rv);
+int setsigvec(proc_t, thread_t, int, struct __kern_sigaction *, boolean_t in_sigstart);
+extern void proc_apply_task_networkbg_internal(proc_t);
/*
* Mach things for which prototypes are unavailable from Mach headers
task_t task);
void ipc_thread_reset(
thread_t thread);
+kern_return_t ipc_object_copyin(
+ ipc_space_t space,
+ mach_port_name_t name,
+ mach_msg_type_name_t msgt_name,
+ ipc_object_t *objectp);
+void ipc_port_release_send(ipc_port_t);
extern struct savearea *get_user_regs(thread_t);
#include <kern/task.h>
#include <kern/ast.h>
#include <kern/mach_loader.h>
+#include <kern/mach_fat.h>
#include <mach-o/fat.h>
#include <mach-o/loader.h>
#include <machine/vmparam.h>
-#if KTRACE
-#include <sys/ktrace.h>
-#endif
#include <sys/imgact.h>
+#include <sys/sdt.h>
+
/*
- * SIZE_MAXPTR The maximum size of a user space pointer, in bytes
- * SIZE_IMG_STRSPACE The available string space, minus two pointers; we
- * define it interms of the maximum, since we don't
- * know the pointer size going in, until after we've
- * parsed the executable image.
+ * EAI_ITERLIMIT The maximum number of times to iterate an image
+ * activator in exec_activate_image() before treating
+ * it as malformed/corrupt.
*/
-#define SIZE_MAXPTR 8 /* 64 bits */
-#define SIZE_IMG_STRSPACE (NCARGS - 2 * SIZE_MAXPTR)
+#define EAI_ITERLIMIT 10
-int app_profile = 0;
+/*
+ * For #! interpreter parsing
+ */
+#define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
+#define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
extern vm_map_t bsd_pageable_map;
extern struct fileops vnops;
#define ROUND_PTR(type, addr) \
- (type *)( ( (unsigned)(addr) + 16 - 1) \
+ (type *)( ( (uintptr_t)(addr) + 16 - 1) \
& ~(16 - 1) )
struct image_params; /* Forward */
+static int exec_activate_image(struct image_params *imgp);
static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
static int load_return_to_errno(load_return_t lrtn);
static int execargs_alloc(struct image_params *imgp);
static int execargs_free(struct image_params *imgp);
static int exec_check_permissions(struct image_params *imgp);
static int exec_extract_strings(struct image_params *imgp);
+static int exec_add_apple_strings(struct image_params *imgp);
static int exec_handle_sugid(struct image_params *imgp);
static int sugid_scripts = 0;
-SYSCTL_INT (_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW, &sugid_scripts, 0, "");
+SYSCTL_INT (_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
static kern_return_t create_unix_stack(vm_map_t map, user_addr_t user_stack,
- int customstack, struct proc *p);
+ int customstack, proc_t p);
static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
+static void exec_resettextvp(proc_t, struct image_params *);
+static int check_for_signature(proc_t, struct image_params *);
-/* XXX forward; should be in headers, but can't be for one reason or another */
-extern void vfork_return(thread_t th_act,
- struct proc * p,
- struct proc *p2,
- register_t *retval);
+/* We don't want this one exported */
+__private_extern__
+int open1(vfs_context_t, struct nameidata *, int, struct vnode_attr *, int32_t *);
/*
- * exec_add_string
+ * exec_add_user_string
*
* Add the requested string to the string space area.
*
* Parameters; struct image_params * image parameter block
* user_addr_t string to add to strings area
- * uio_seg segment where string is located
+ * int segment from which string comes
+ * boolean_t TRUE if string contributes to NCARGS
*
* Returns: 0 Success
* !0 Failure errno from copyinstr()
* Implicit returns:
* (imgp->ip_strendp) updated location of next add, if any
* (imgp->ip_strspace) updated byte count of space remaining
+ * (imgp->ip_argspace) updated byte count of space in NCARGS
*/
static int
-exec_add_string(struct image_params *imgp, user_addr_t str, /*uio_seg*/int seg)
+exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
{
- int error = 0;
-
- do {
- size_t len = 0;
- if (imgp->ip_strspace <= 0) {
+ int error = 0;
+
+ do {
+ size_t len = 0;
+ int space;
+
+ if (is_ncargs)
+ space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
+ else
+ space = imgp->ip_strspace;
+
+ if (space <= 0) {
error = E2BIG;
break;
}
- if (IS_UIO_SYS_SPACE(seg)) {
+
+ if (!UIO_SEG_IS_USER_SPACE(seg)) {
char *kstr = CAST_DOWN(char *,str); /* SAFE */
- error = copystr(kstr, imgp->ip_strendp, imgp->ip_strspace, &len);
+ error = copystr(kstr, imgp->ip_strendp, space, &len);
} else {
- error = copyinstr(str, imgp->ip_strendp, imgp->ip_strspace,
- &len);
+ error = copyinstr(str, imgp->ip_strendp, space, &len);
}
+
imgp->ip_strendp += len;
imgp->ip_strspace -= len;
+ if (is_ncargs)
+ imgp->ip_argspace -= len;
+
} while (error == ENAMETOOLONG);
-
+
return error;
}
* To support new app package launching for Mac OS X, the dyld needs the
* first argument to execve() stored on the user stack.
*
- * Save the executable path name at the top of the strings area and set
+ * Save the executable path name at the bottom of the strings area and set
* the argument vector pointer to the location following that to indicate
* the start of the argument and environment tuples, setting the remaining
- * string space count to the size of the string area minus the path length
- * and a reserve for two pointers.
+ * string space count to the size of the string area minus the path length.
*
* Parameters; struct image_params * image parameter block
* char * path used to invoke program
- * uio_seg segment where path is located
+ * int segment from which path comes
*
* Returns: int 0 Success
- * !0 Failure: error number
+ * EFAULT Bad address
+ * copy[in]str:EFAULT Bad address
+ * copy[in]str:ENAMETOOLONG Filename too long
+ *
* Implicit returns:
* (imgp->ip_strings) saved path
* (imgp->ip_strspace) space remaining in ip_strings
- * (imgp->ip_argv) beginning of argument list
* (imgp->ip_strendp) start of remaining copy area
+ * (imgp->ip_argspace) space remaining of NCARGS
+ * (imgp->ip_applec) Initial applev[0]
*
* Note: We have to do this before the initial namei() since in the
* path contains symbolic links, namei() will overwrite the
* unacceptable for dyld.
*/
static int
-exec_save_path(struct image_params *imgp, user_addr_t path, /*uio_seg*/int seg)
+exec_save_path(struct image_params *imgp, user_addr_t path, int seg)
{
int error;
size_t len;
- char *kpath = CAST_DOWN(char *,path); /* SAFE */
-
- imgp->ip_strendp = imgp->ip_strings;
- imgp->ip_strspace = SIZE_IMG_STRSPACE;
+ char *kpath;
len = MIN(MAXPATHLEN, imgp->ip_strspace);
- switch( seg) {
+ switch(seg) {
case UIO_USERSPACE32:
case UIO_USERSPACE64: /* Same for copyin()... */
error = copyinstr(path, imgp->ip_strings, len, &len);
break;
- case UIO_SYSSPACE32:
+ case UIO_SYSSPACE:
+ kpath = CAST_DOWN(char *,path); /* SAFE */
error = copystr(kpath, imgp->ip_strings, len, &len);
break;
default:
if (!error) {
imgp->ip_strendp += len;
imgp->ip_strspace -= len;
- imgp->ip_argv = imgp->ip_strendp;
}
return(error);
}
+/*
+ * exec_reset_save_path
+ *
+ * If we detect a shell script, we need to reset the string area
+ * state so that the interpreter can be saved onto the stack.
+
+ * Parameters; struct image_params * image parameter block
+ *
+ * Returns: int 0 Success
+ *
+ * Implicit returns:
+ * (imgp->ip_strings) saved path
+ * (imgp->ip_strspace) space remaining in ip_strings
+ * (imgp->ip_strendp) start of remaining copy area
+ * (imgp->ip_argspace) space remaining of NCARGS
+ *
+ */
+static int
+exec_reset_save_path(struct image_params *imgp)
+{
+ imgp->ip_strendp = imgp->ip_strings;
+ imgp->ip_argspace = NCARGS;
+ imgp->ip_strspace = ( NCARGS + PAGE_SIZE );
+
+ return (0);
+}
+
#ifdef IMGPF_POWERPC
/*
* exec_powerpc32_imgact
* Make sure it's a PowerPC binary. If we've already redirected
* from an interpreted file once, don't do it again.
*/
- if (mach_header->magic != MH_CIGAM)
+ if (mach_header->magic != MH_CIGAM) {
+ /*
+ * If it's a cross-architecture 64 bit binary, then claim
+ * it, but refuse to run it.
+ */
+ if (mach_header->magic == MH_CIGAM_64)
+ return (EBADARCH);
return (-1);
+ }
/* If there is no exec_archhandler_ppc, we can't run it */
if (exec_archhandler_ppc.path[0] == 0)
return (EBADARCH);
+ /* Remember the type of the original file for later grading */
+ if (!imgp->ip_origcputype) {
+ imgp->ip_origcputype =
+ OSSwapBigToHostInt32(mach_header->cputype);
+ imgp->ip_origcpusubtype =
+ OSSwapBigToHostInt32(mach_header->cpusubtype);
+ }
+
/*
* The PowerPC flag will be set by the exec_check_permissions()
* call anyway; however, we set this flag here so that the relookup
imgp->ip_flags |= IMGPF_POWERPC;
/* impute an interpreter */
- error = copystr(exec_archhandler_ppc.path, imgp->ip_interp_name,
+ error = copystr(exec_archhandler_ppc.path, imgp->ip_interp_buffer,
IMG_SHSIZE, &len);
if (error)
return (error);
+ exec_reset_save_path(imgp);
+ exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
+ UIO_SYSSPACE);
+
/*
* provide a replacement string for p->p_comm; we have to use an
- * an alternate buffer for this, rather than replacing it directly,
+ * alternate buffer for this, rather than replacing it directly,
* since the exec may fail and return to the parent. In that case,
* we would have erroneously changed the parent p->p_comm instead.
*/
- strncpy(imgp->ip_p_comm, imgp->ip_ndp->ni_cnd.cn_nameptr, MAXCOMLEN);
- imgp->ip_p_comm[MAXCOMLEN] = '\0';
+ strlcpy(imgp->ip_p_comm, imgp->ip_ndp->ni_cnd.cn_nameptr, MAXCOMLEN+1);
+ /* +1 to allow MAXCOMLEN characters to be copied */
return (-3);
}
{
char *vdata = imgp->ip_vdata;
char *ihp;
- char *line_endp;
+ char *line_startp, *line_endp;
char *interp;
+ proc_t p;
+ struct fileproc *fp;
+ int fd;
+ int error;
/*
* Make sure it's a shell script. If we've already redirected
#endif /* IMGPF_POWERPC */
imgp->ip_flags |= IMGPF_INTERPRET;
+ imgp->ip_interp_sugid_fd = -1;
+ imgp->ip_interp_buffer[0] = '\0';
- /* Check to see if SUGID scripts are permitted. If they aren't then
+ /* Check to see if SUGID scripts are permitted. If they aren't then
* clear the SUGID bits.
* imgp->ip_vattr is known to be valid.
- */
- if (sugid_scripts == 0) {
- imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
+ */
+ if (sugid_scripts == 0) {
+ imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
}
- /* Find the nominal end of the interpreter line */
- for( ihp = &vdata[2]; *ihp != '\n' && *ihp != '#'; ihp++) {
- if (ihp >= &vdata[IMG_SHSIZE])
+ /* Try to find the first non-whitespace character */
+ for( ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++ ) {
+ if (IS_EOL(*ihp)) {
+ /* Did not find interpreter, "#!\n" */
return (ENOEXEC);
+ } else if (IS_WHITESPACE(*ihp)) {
+ /* Whitespace, like "#! /bin/sh\n", keep going. */
+ } else {
+ /* Found start of interpreter */
+ break;
+ }
+ }
+
+ if (ihp == &vdata[IMG_SHSIZE]) {
+ /* All whitespace, like "#! " */
+ return (ENOEXEC);
}
- line_endp = ihp;
- ihp = &vdata[2];
- /* Skip over leading spaces - until the interpreter name */
- while ( ihp < line_endp && ((*ihp == ' ') || (*ihp == '\t')))
- ihp++;
+ line_startp = ihp;
- /*
- * Find the last non-whitespace character before the end of line or
- * the beginning of a comment; this is our new end of line.
- */
- for (;line_endp > ihp && ((*line_endp == ' ') || (*line_endp == '\t')); line_endp--)
- continue;
+ /* Try to find the end of the interpreter+args string */
+ for ( ; ihp < &vdata[IMG_SHSIZE]; ihp++ ) {
+ if (IS_EOL(*ihp)) {
+ /* Got it */
+ break;
+ } else {
+ /* Still part of interpreter or args */
+ }
+ }
- /* Empty? */
- if (line_endp == ihp)
+ if (ihp == &vdata[IMG_SHSIZE]) {
+ /* A long line, like "#! blah blah blah" without end */
return (ENOEXEC);
+ }
+
+ /* Backtrack until we find the last non-whitespace */
+ while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
+ ihp--;
+ }
+
+ /* The character after the last non-whitespace is our logical end of line */
+ line_endp = ihp + 1;
+
+ /*
+ * Now we have pointers to the usable part of:
+ *
+ * "#! /usr/bin/int first second third \n"
+ * ^ line_startp ^ line_endp
+ */
/* copy the interpreter name */
- interp = imgp->ip_interp_name;
- while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
- *interp++ = *ihp++;
+ interp = imgp->ip_interp_buffer;
+ for ( ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++)
+ *interp++ = *ihp;
*interp = '\0';
- exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_name),
- UIO_SYSSPACE32);
+ exec_reset_save_path(imgp);
+ exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
+ UIO_SYSSPACE);
- ihp = &vdata[2];
- while (ihp < line_endp) {
- /* Skip leading whitespace before each argument */
- while ((*ihp == ' ') || (*ihp == '\t'))
- ihp++;
+ /* Copy the entire interpreter + args for later processing into argv[] */
+ interp = imgp->ip_interp_buffer;
+ for ( ihp = line_startp; (ihp < line_endp); ihp++)
+ *interp++ = *ihp;
+ *interp = '\0';
- if (ihp >= line_endp)
- break;
+ /*
+ * If we have a SUID oder SGID script, create a file descriptor
+ * from the vnode and pass /dev/fd/%d instead of the actual
+ * path name so that the script does not get opened twice
+ */
+ if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
+ p = vfs_context_proc(imgp->ip_vfs_context);
+ error = falloc(p, &fp, &fd, imgp->ip_vfs_context);
+ if (error)
+ return(error);
- /* We have an argument; copy it */
- while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
- *imgp->ip_strendp++ = *ihp++;
- imgp->ip_strspace--;
- }
- *imgp->ip_strendp++ = 0;
- imgp->ip_strspace--;
- imgp->ip_argc++;
+ fp->f_fglob->fg_flag = FREAD;
+ fp->f_fglob->fg_type = DTYPE_VNODE;
+ fp->f_fglob->fg_ops = &vnops;
+ fp->f_fglob->fg_data = (caddr_t)imgp->ip_vp;
+
+ proc_fdlock(p);
+ procfdtbl_releasefd(p, fd, NULL);
+ fp_drop(p, fd, fp, 1);
+ proc_fdunlock(p);
+ vnode_ref(imgp->ip_vp);
+
+ imgp->ip_interp_sugid_fd = fd;
}
return (-3);
* reloading the first page for the image with a first page from the
* offset location indicated by the fat header.
*
+ * Parameters; struct image_params * image parameter block
+ *
+ * Returns: -1 not a fat binary (keep looking)
+ * -2 Success: encapsulated binary: reread
+ * >0 Failure: error number
+ *
* Important: This image activator is byte order neutral.
*
- * Note: If we find an encapsulated binary, we make no assertions
+ * Note: A return value other than -1 indicates subsequent image
+ * activators should not be given the opportunity to attempt
+ * to activate the image.
+ *
+ * If we find an encapsulated binary, we make no assertions
* about its validity; instead, we leave that up to a rescan
* for an activator to claim it, and, if it is claimed by one,
* that activator is responsible for determining validity.
static int
exec_fat_imgact(struct image_params *imgp)
{
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
kauth_cred_t cred = kauth_cred_proc_ref(p);
struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
+ struct _posix_spawnattr *psa = NULL;
struct fat_arch fat_arch;
int resid, error;
load_return_t lret;
goto bad;
}
+ /* If posix_spawn binprefs exist, respect those prefs. */
+ psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
+ if (psa != NULL && psa->psa_binprefs[0] != 0) {
+ struct fat_arch *arches = (struct fat_arch *) (fat_header + 1);
+ int nfat_arch = 0, pr = 0, f = 0;
+
+ nfat_arch = OSSwapBigToHostInt32(fat_header->nfat_arch);
+ /* Check each preference listed against all arches in header */
+ for (pr = 0; pr < NBINPREFS; pr++) {
+ cpu_type_t pref = psa->psa_binprefs[pr];
+ if (pref == 0) {
+ /* No suitable arch in the pref list */
+ error = EBADARCH;
+ goto bad;
+ }
+
+ if (pref == CPU_TYPE_ANY) {
+ /* Fall through to regular grading */
+ break;
+ }
+
+ for (f = 0; f < nfat_arch; f++) {
+ cpu_type_t archtype = OSSwapBigToHostInt32(
+ arches[f].cputype);
+ cpu_type_t archsubtype = OSSwapBigToHostInt32(
+ arches[f].cpusubtype) & ~CPU_SUBTYPE_MASK;
+ if (pref == archtype &&
+ grade_binary(archtype, archsubtype)) {
+ /* We have a winner! */
+ fat_arch.cputype = archtype;
+ fat_arch.cpusubtype = archsubtype;
+ fat_arch.offset = OSSwapBigToHostInt32(
+ arches[f].offset);
+ fat_arch.size = OSSwapBigToHostInt32(
+ arches[f].size);
+ fat_arch.align = OSSwapBigToHostInt32(
+ arches[f].align);
+ goto use_arch;
+ }
+ }
+ }
+ }
+
/* Look up our preferred architecture in the fat file. */
lret = fatfile_getarch_affinity(imgp->ip_vp,
(vm_offset_t)fat_header,
goto bad;
}
- /* Read the Mach-O header out of it */
+use_arch:
+ /* Read the Mach-O header out of fat_arch */
error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
PAGE_SIZE, fat_arch.offset,
- UIO_SYSSPACE32, (IO_UNIT|IO_NODELOCKED),
+ UIO_SYSSPACE, (IO_UNIT|IO_NODELOCKED),
cred, &resid, p);
if (error) {
goto bad;
*
* Image activator for mach-o 1.0 binaries.
*
+ * Parameters; struct image_params * image parameter block
+ *
+ * Returns: -1 not a fat binary (keep looking)
+ * -2 Success: encapsulated binary: reread
+ * >0 Failure: error number
+ * EBADARCH Mach-o binary, but with an unrecognized
+ * architecture
+ * ENOMEM No memory for child process after -
+ * can only happen after vfork()
+ *
* Important: This image activator is NOT byte order neutral.
+ *
+ * Note: A return value other than -1 indicates subsequent image
+ * activators should not be given the opportunity to attempt
+ * to activate the image.
+ *
+ * TODO: More gracefully handle failures after vfork
*/
static int
exec_mach_imgact(struct image_params *imgp)
{
struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
- kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int error = 0;
int vfexec = 0;
task_t task;
- task_t new_task;
+ task_t new_task = NULL; /* protected by vfexec */
thread_t thread;
struct uthread *uthread;
vm_map_t old_map = VM_MAP_NULL;
vm_map_t map;
- boolean_t clean_regions = FALSE;
load_return_t lret;
load_result_t load_result;
- shared_region_mapping_t shared_region, initial_region;
-#ifdef IMGPF_POWERPC
- int powerpcParent, powerpcImage;
-#endif /* IMGPF_POWERPC */
-
+ struct _posix_spawnattr *psa = NULL;
+ int spawn = (imgp->ip_flags & IMGPF_SPAWN);
+ int apptype = 0;
+
/*
* make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
* is a reserved field on the end, so for the most part, we can
*/
if ((mach_header->magic != MH_MAGIC) &&
(mach_header->magic != MH_MAGIC_64)) {
- error = -1;
+ error = -1;
+ goto bad;
+ }
+
+ switch (mach_header->filetype) {
+ case MH_DYLIB:
+ case MH_BUNDLE:
+ error = -1;
goto bad;
}
+ if (!imgp->ip_origcputype) {
+ imgp->ip_origcputype = mach_header->cputype;
+ imgp->ip_origcpusubtype = mach_header->cpusubtype;
+ }
+
task = current_task();
thread = current_thread();
uthread = get_bsdthread_info(thread);
+ /*
+ * Save off the vfexec state up front; we have to do this, because
+ * we need to know if we were in this state initially subsequent to
+ * creating the backing task, thread, and uthread for the child
+ * process (from the vfs_context_t from in img_parms).
+ */
if (uthread->uu_flag & UT_VFORK)
vfexec = 1; /* Mark in exec */
if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64)
imgp->ip_flags |= IMGPF_IS_64BIT;
- if (!grade_binary(mach_header->cputype, mach_header->cpusubtype)) {
+ /* If posix_spawn binprefs exist, respect those prefs. */
+ psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
+ if (psa != NULL && psa->psa_binprefs[0] != 0) {
+ int pr = 0;
+ for (pr = 0; pr < NBINPREFS; pr++) {
+ cpu_type_t pref = psa->psa_binprefs[pr];
+ if (pref == 0) {
+ /* No suitable arch in the pref list */
+ error = EBADARCH;
+ goto bad;
+ }
+
+ if (pref == CPU_TYPE_ANY) {
+ /* Jump to regular grading */
+ goto grade;
+ }
+
+ if (pref == imgp->ip_origcputype) {
+ /* We have a match! */
+ goto grade;
+ }
+ }
error = EBADARCH;
goto bad;
}
-
- /*
- * Copy in arguments/environment from the old process, if the
- * vector is non-NULL (i.e. exec is not being called from
- * load_init_program(), as a special case, at system startup).
- */
- if (imgp->ip_user_argv != 0LL) {
- error = exec_extract_strings(imgp);
- if (error)
- goto bad;
+grade:
+ if (!grade_binary(imgp->ip_origcputype & ~CPU_SUBTYPE_LIB64,
+ imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK)) {
+ error = EBADARCH;
+ goto bad;
}
- /*
- * Hack for binary compatability; put three NULs on the end of the
- * string area, and round it up to the next word boundary. This
- * ensures padding with NULs to the boundary.
- */
- imgp->ip_strendp[0] = 0;
- imgp->ip_strendp[1] = 0;
- imgp->ip_strendp[2] = 0;
- imgp->ip_strendp += (((imgp->ip_strendp - imgp->ip_strings) + NBPW-1) & ~(NBPW-1));
+ /* Copy in arguments/environment from the old process */
+ error = exec_extract_strings(imgp);
+ if (error)
+ goto bad;
+
+ error = exec_add_apple_strings(imgp);
+ if (error)
+ goto bad;
+
+ AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
+ imgp->ip_endargv - imgp->ip_startargv);
+ AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
+ imgp->ip_endenvv - imgp->ip_endargv);
#ifdef IMGPF_POWERPC
/*
* Should be factored out; this is here because we might be getting
* invoked this way as the result of a shell script, and the check
* in exec_check_permissions() is not interior to the jump back up
- * to the "encapsulated_binary:" label in execve().
+ * to the "encapsulated_binary:" label in exec_activate_image().
*/
if (imgp->ip_vattr->va_fsid == exec_archhandler_ppc.fsid &&
- imgp->ip_vattr->va_fileid == (uint64_t)((u_long)exec_archhandler_ppc.fileid)) {
+ imgp->ip_vattr->va_fileid == exec_archhandler_ppc.fileid) {
imgp->ip_flags |= IMGPF_POWERPC;
}
#endif /* IMGPF_POWERPC */
- if (vfexec) {
- kern_return_t result;
-
- result = task_create_internal(task, FALSE, (imgp->ip_flags & IMGPF_IS_64BIT), &new_task);
- if (result != KERN_SUCCESS)
- printf("execve: task_create failed. Code: 0x%x\n", result);
- p->task = new_task;
- set_bsdtask_info(new_task, p);
- if (p->p_nice != 0)
- resetpriority(p);
- map = get_task_map(new_task);
+ /*
+ * We are being called to activate an image subsequent to a vfork()
+ * operation; in this case, we know that our task, thread, and
+ * uthread are actually those of our parent, and our proc, which we
+ * obtained indirectly from the image_params vfs_context_t, is the
+ * new child process.
+ */
+ if (vfexec || spawn) {
+ if (vfexec) {
+ imgp->ip_new_thread = fork_create_child(task, p, FALSE, (imgp->ip_flags & IMGPF_IS_64BIT));
+ if (imgp->ip_new_thread == NULL) {
+ error = ENOMEM;
+ goto bad;
+ }
+ }
- if (imgp->ip_flags & IMGPF_IS_64BIT)
- vm_map_set_64bit(map);
- else
- vm_map_set_32bit(map);
-
- result = thread_create(new_task, &imgp->ip_vfork_thread);
- if (result != KERN_SUCCESS)
- printf("execve: thread_create failed. Code: 0x%x\n", result);
- /* reset local idea of task, thread, uthread */
- task = new_task;
- thread = imgp->ip_vfork_thread;
+ /* reset local idea of thread, uthread, task */
+ thread = imgp->ip_new_thread;
uthread = get_bsdthread_info(thread);
+ task = new_task = get_threadtask(thread);
+ map = get_task_map(task);
} else {
map = VM_MAP_NULL;
}
* We set these flags here; this is OK, since if we fail after
* this point, we have already destroyed the parent process anyway.
*/
+ task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
if (imgp->ip_flags & IMGPF_IS_64BIT) {
task_set_64bit(task, TRUE);
- p->p_flag |= P_LP64;
+ OSBitOrAtomic(P_LP64, &p->p_flag);
} else {
task_set_64bit(task, FALSE);
- p->p_flag &= ~P_LP64;
+ OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
}
/*
* Load the Mach-O file.
- */
-/* LP64 - remove following "if" statement after osfmk/vm/task_working_set.c */
-if((imgp->ip_flags & IMGPF_IS_64BIT) == 0)
- if(imgp->ip_tws_cache_name) {
- tws_handle_startup_file(task, kauth_cred_getuid(cred),
- imgp->ip_tws_cache_name, imgp->ip_vp, &clean_regions);
- }
-
- vm_get_shared_region(task, &initial_region);
-
-#ifdef IMGPF_POWERPC
- /*
- * If we are transitioning to/from powerpc, then we need to do extra
- * work here.
- */
- powerpcParent = (p->p_flag & P_TRANSLATED) ? 1 : 0;
- powerpcImage = (imgp->ip_flags & IMGPF_POWERPC) ? 1 : 0;
-
- if (powerpcParent ^ powerpcImage) {
- cpu_type_t cpu = (powerpcImage ? CPU_TYPE_POWERPC : cpu_type());
- struct vnode *rootDir = p->p_fd->fd_rdir;
-
- shared_region = lookup_default_shared_region((int)rootDir, cpu);
- if (shared_region == NULL) {
- shared_region_mapping_t old_region;
- shared_region_mapping_t new_region;
- vm_get_shared_region(current_task(), &old_region);
- /* grrrr... this sets current_task(), not task
- * -- they're different (usually)
- */
- shared_file_boot_time_init((int)rootDir,cpu);
- if ( current_task() != task ) {
- vm_get_shared_region(current_task(),&new_region);
- vm_set_shared_region(task,new_region);
- vm_set_shared_region(current_task(),old_region);
- }
- } else {
- vm_set_shared_region(task, shared_region);
- }
- shared_region_mapping_dealloc(initial_region);
- } else
-#endif /* IMGPF_POWERPC */
-
- {
- struct shared_region_task_mappings map_info;
- shared_region_mapping_t next;
-
- shared_region_mapping_info(initial_region,
- &map_info.text_region,
- &map_info.text_size,
- &map_info.data_region,
- &map_info.data_size,
- &map_info.region_mappings,
- &map_info.client_base,
- &map_info.alternate_base,
- &map_info.alternate_next,
- &map_info.fs_base,
- &map_info.system,
- &map_info.flags,
- &next);
- if (map_info.flags & SHARED_REGION_STANDALONE) {
- /*
- * We were using a private shared region.
- * Try and get back to a system-wide shared region
- * with matching "fs_base" (for chroot) and "system"
- * (for CPU type).
- */
- shared_region = lookup_default_shared_region(
- map_info.fs_base,
- map_info.system);
- if (shared_region == NULL) {
- /*
- * No system-wide default regions, stick to
- * our private region...
- */
- } else {
- SHARED_REGION_TRACE(
- SHARED_REGION_TRACE_INFO,
- ("shared_region: %p [%d(%s)] "
- "exec(\"%s\"): "
- "moving from private %p[%x,%x,%x] "
- "to default %p\n",
- current_thread(),
- p->p_pid, p->p_comm,
- (imgp->ip_p_comm[0] ?
- imgp->ip_p_comm :
- imgp->ip_ndp->ni_cnd.cn_nameptr),
- initial_region,
- map_info.fs_base,
- map_info.system,
- map_info.flags,
- shared_region));
- vm_set_shared_region(task, shared_region);
- shared_region_mapping_dealloc(initial_region);
- }
- }
- }
-
- /*
+ *
* NOTE: An error after this point indicates we have potentially
- * destroyed or overwrote some process state while attempting an
+ * destroyed or overwritten some process state while attempting an
* execve() following a vfork(), which is an unrecoverable condition.
*/
- /*
- * We reset the task to 64-bit (or not) here. It may have picked up
- * a new map, and we need that to reflect its true 64-bit nature.
- */
-
- task_set_64bit(task,
- ((imgp->ip_flags & IMGPF_IS_64BIT) == IMGPF_IS_64BIT));
-
/*
* Actually load the image file we previously decided to load.
*/
- lret = load_machfile(imgp, mach_header, thread, map, clean_regions, &load_result);
+ lret = load_machfile(imgp, mach_header, thread, map, &load_result);
if (lret != LOAD_SUCCESS) {
error = load_return_to_errno(lret);
goto badtoolate;
}
- /* load_machfile() maps the vnode */
- (void)ubc_map(imgp->ip_vp, PROT_EXEC);
-
+ vm_map_set_user_wire_limit(get_task_map(task), p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
+
+ /*
+ * Set code-signing flags if this binary is signed, or if parent has
+ * requested them on exec.
+ */
+ if (load_result.csflags & CS_VALID) {
+ imgp->ip_csflags |= load_result.csflags &
+ (CS_VALID|
+ CS_HARD|CS_KILL|CS_EXEC_SET_HARD|CS_EXEC_SET_KILL);
+ } else {
+ imgp->ip_csflags &= ~CS_VALID;
+ }
+
+ if (p->p_csflags & CS_EXEC_SET_HARD)
+ imgp->ip_csflags |= CS_HARD;
+ if (p->p_csflags & CS_EXEC_SET_KILL)
+ imgp->ip_csflags |= CS_KILL;
+
+
+ /*
+ * Set up the system reserved areas in the new address space.
+ */
+ vm_map_exec(get_task_map(task),
+ task,
+ (void *) p->p_fd->fd_rdir,
+#ifdef IMGPF_POWERPC
+ imgp->ip_flags & IMGPF_POWERPC ?
+ CPU_TYPE_POWERPC :
+#endif
+ cpu_type());
+
/*
- * Close file descriptors
- * which specify close-on-exec.
+ * Close file descriptors which specify close-on-exec.
*/
- fdexec(p);
+ fdexec(p, psa != NULL ? psa->psa_flags : 0);
/*
* deal with set[ug]id.
*/
error = exec_handle_sugid(imgp);
- KNOTE(&p->p_klist, NOTE_EXEC);
-
- if (!vfexec && (p->p_flag & P_TRACED))
+ /* Make sure we won't interrupt ourself signalling a partial process */
+ if (!vfexec && !spawn && (p->p_lflag & P_LTRACED))
psignal(p, SIGTRAP);
if (error) {
goto badtoolate;
}
- vnode_put(imgp->ip_vp);
- imgp->ip_vp = NULL;
if (load_result.unixproc &&
create_unix_stack(get_task_map(task),
- load_result.user_stack, load_result.customstack, p)) {
+ load_result.user_stack,
+ load_result.customstack,
+ p) != KERN_SUCCESS) {
error = load_return_to_errno(LOAD_NOSPACE);
goto badtoolate;
}
- if (vfexec) {
+ if (vfexec || spawn) {
old_map = vm_map_switch(get_task_map(task));
}
ap = p->user_stack;
error = exec_copyout_strings(imgp, &ap);
if (error) {
- if (vfexec)
+ if (vfexec || spawn)
vm_map_switch(old_map);
goto badtoolate;
}
if (load_result.dynlinker) {
uint64_t ap;
+ int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
/* Adjust the stack */
- if (imgp->ip_flags & IMGPF_IS_64BIT) {
- ap = thread_adjuserstack(thread, -8);
- error = copyoutptr(load_result.mach_header, ap, 8);
- } else {
- ap = thread_adjuserstack(thread, -4);
- error = suword(ap, load_result.mach_header);
- }
+ ap = thread_adjuserstack(thread, -new_ptr_size);
+ error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
+
if (error) {
- if (vfexec)
- vm_map_switch(old_map);
+ if (vfexec || spawn)
+ vm_map_switch(old_map);
goto badtoolate;
}
+ task_set_dyld_info(task, load_result.all_image_info_addr,
+ load_result.all_image_info_size);
}
- if (vfexec) {
+ if (vfexec || spawn) {
vm_map_switch(old_map);
}
/* Set the entry point */
*/
_aio_exec( p );
+#if SYSV_SHM
/* FIXME: Till vmspace inherit is fixed: */
if (!vfexec && p->vm_shm)
shmexec(p);
+#endif
+#if SYSV_SEM
/* Clean up the semaphores */
semexit(p);
+#endif
/*
* Remember file name for accounting.
p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
}
+ pal_dbg_set_task_name( p->task );
+
+ memcpy(&p->p_uuid[0], &load_result.uuid[0], sizeof(p->p_uuid));
+
+// <rdar://6598155> dtrace code cleanup needed
+#if CONFIG_DTRACE
+ /*
+ * Invalidate any predicate evaluation already cached for this thread by DTrace.
+ * That's because we've just stored to p_comm and DTrace refers to that when it
+ * evaluates the "execname" special variable. uid and gid may have changed as well.
+ */
+ dtrace_set_thread_predcache(current_thread(), 0);
+
+ /*
+ * Free any outstanding lazy dof entries. It is imperative we
+ * always call dtrace_lazy_dofs_destroy, rather than null check
+ * and call if !NULL. If we NULL test, during lazy dof faulting
+ * we can race with the faulting code and proceed from here to
+ * beyond the helpers cleanup. The lazy dof faulting will then
+ * install new helpers which no longer belong to this process!
+ */
+ dtrace_lazy_dofs_destroy(p);
+
+
+ /*
+ * Clean up any DTrace helpers for the process.
+ */
+ if (p->p_dtrace_helpers != NULL && dtrace_helpers_cleanup) {
+ (*dtrace_helpers_cleanup)(p);
+ }
+
+ /*
+ * Cleanup the DTrace provider associated with this process.
+ */
+ proc_lock(p);
+ if (p->p_dtrace_probes && dtrace_fasttrap_exec_ptr) {
+ (*dtrace_fasttrap_exec_ptr)(p);
+ }
+ proc_unlock(p);
+#endif
+
if (kdebug_enable) {
- long dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4;
-
- /*
- * Collect the pathname for tracing
- */
- kdbg_trace_string(p, &dbg_arg1, &dbg_arg2, &dbg_arg3, &dbg_arg4);
-
- if (vfexec)
- {
- KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
- p->p_pid ,0,0,0, (unsigned int)thread);
- KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
- dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, (unsigned int)thread);
- }
- else
- {
- KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
- p->p_pid ,0,0,0,0);
- KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
- dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, 0);
- }
+ long dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4;
+
+ /*
+ * Collect the pathname for tracing
+ */
+ kdbg_trace_string(p, &dbg_arg1, &dbg_arg2, &dbg_arg3, &dbg_arg4);
+
+ if (vfexec || spawn) {
+ KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
+ p->p_pid ,0,0,0, (uintptr_t)thread_tid(thread));
+ KERNEL_DEBUG_CONSTANT1((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
+ dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, (uintptr_t)thread_tid(thread));
+ } else {
+ KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_DATA, 2)) | DBG_FUNC_NONE,
+ p->p_pid ,0,0,0,0);
+ KERNEL_DEBUG_CONSTANT((TRACEDBG_CODE(DBG_TRACE_STRING, 2)) | DBG_FUNC_NONE,
+ dbg_arg1, dbg_arg2, dbg_arg3, dbg_arg4, 0);
+ }
}
#ifdef IMGPF_POWERPC
* from the process.
*/
if (((imgp->ip_flags & IMGPF_POWERPC) != 0))
- p->p_flag |= P_TRANSLATED;
+ OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
else
#endif /* IMGPF_POWERPC */
- p->p_flag &= ~P_TRANSLATED;
- p->p_flag &= ~P_AFFINITY;
+ OSBitAndAtomic(~((uint32_t)P_TRANSLATED), &p->p_flag);
+ OSBitAndAtomic(~((uint32_t)P_AFFINITY), &p->p_flag);
+
+ /*
+ * If posix_spawned with the START_SUSPENDED flag, stop the
+ * process before it runs.
+ */
+ if (imgp->ip_px_sa != NULL) {
+ psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
+ if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
+ proc_lock(p);
+ p->p_stat = SSTOP;
+ proc_unlock(p);
+ (void) task_suspend(p->task);
+ }
+ if ((psa->psa_flags & POSIX_SPAWN_OSX_TALAPP_START) || (psa->psa_flags & POSIX_SPAWN_OSX_DBCLIENT_START) || (psa->psa_flags & POSIX_SPAWN_IOS_APP_START)) {
+ if ((psa->psa_flags & POSIX_SPAWN_OSX_TALAPP_START))
+ apptype = PROC_POLICY_OSX_APPTYPE_TAL;
+ else if (psa->psa_flags & POSIX_SPAWN_OSX_DBCLIENT_START)
+ apptype = PROC_POLICY_OSX_APPTYPE_DBCLIENT;
+ else if (psa->psa_flags & POSIX_SPAWN_IOS_APP_START)
+ apptype = PROC_POLICY_IOS_APPTYPE;
+ else
+ apptype = 0;
+ proc_set_task_apptype(p->task, apptype);
+ if ((apptype == PROC_POLICY_OSX_APPTYPE_TAL) ||
+ (apptype == PROC_POLICY_OSX_APPTYPE_DBCLIENT)) {
+
+ proc_apply_task_networkbg_internal(p);
+ }
+ }
+ }
/*
* mark as execed, wakeup the process that vforked (if any) and tell
- * it that it now has it's own resources back
+ * it that it now has its own resources back
*/
- p->p_flag |= P_EXEC;
- if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
- p->p_flag &= ~P_PPWAIT;
+ OSBitOrAtomic(P_EXEC, &p->p_flag);
+ proc_resetregister(p);
+ if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
+ proc_lock(p);
+ p->p_lflag &= ~P_LPPWAIT;
+ proc_unlock(p);
wakeup((caddr_t)p->p_pptr);
}
- if (vfexec && (p->p_flag & P_TRACED)) {
+ /*
+ * Pay for our earlier safety; deliver the delayed signals from
+ * the incomplete vfexec process now that it's complete.
+ */
+ if (vfexec && (p->p_lflag & P_LTRACED)) {
psignal_vfork(p, new_task, thread, SIGTRAP);
}
badtoolate:
- if (vfexec) {
+if (!spawn)
+ proc_knote(p, NOTE_EXEC);
+
+ if (vfexec || spawn) {
task_deallocate(new_task);
thread_deallocate(thread);
if (error)
/*
- * TODO: Dynamic linker header address on stack is copied via suword()
+ * exec_activate_image
+ *
+ * Description: Iterate through the available image activators, and activate
+ * the image associated with the imgp structure. We start with
+ * the
+ *
+ * Parameters: struct image_params * Image parameter block
+ *
+ * Returns: 0 Success
+ * EBADEXEC The executable is corrupt/unknown
+ * execargs_alloc:EINVAL Invalid argument
+ * execargs_alloc:EACCES Permission denied
+ * execargs_alloc:EINTR Interrupted function
+ * execargs_alloc:ENOMEM Not enough space
+ * exec_save_path:EFAULT Bad address
+ * exec_save_path:ENAMETOOLONG Filename too long
+ * exec_check_permissions:EACCES Permission denied
+ * exec_check_permissions:ENOEXEC Executable file format error
+ * exec_check_permissions:ETXTBSY Text file busy [misuse of error code]
+ * exec_check_permissions:???
+ * namei:???
+ * vn_rdwr:??? [anything vn_rdwr can return]
+ * <ex_imgact>:??? [anything an imgact can return]
*/
-/* ARGSUSED */
-int
-execve(struct proc *p, struct execve_args *uap, register_t *retval)
+static int
+exec_activate_image(struct image_params *imgp)
{
- kauth_cred_t cred = kauth_cred_proc_ref(p);
- struct image_params image_params, *imgp;
- struct vnode_attr va;
- struct vnode_attr origva;
struct nameidata nd;
- struct uthread *uthread;
- int i;
- int resid, error;
- task_t task;
- int numthreads;
- int vfexec=0;
+ int error;
+ int resid;
int once = 1; /* save SGUID-ness for interpreted files */
- char alt_p_comm[sizeof(p->p_comm)] = {0}; /* for PowerPC */
- int is_64 = IS_64BIT_PROCESS(p);
- int seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
- struct vfs_context context;
+ int i;
+ int iterlimit = EAI_ITERLIMIT;
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
- context.vc_proc = p;
- context.vc_ucred = cred; /* XXX must NOT be kauth_cred_get() */
+ error = execargs_alloc(imgp);
+ if (error)
+ goto bad;
+
+ error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg);
+ if (error) {
+ goto bad_notrans;
+ }
+ /* Use imgp->ip_strings, which contains the copyin-ed exec path */
+ DTRACE_PROC1(exec, uintptr_t, imgp->ip_strings);
- imgp = &image_params;
+ NDINIT(&nd, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
+ UIO_SYSSPACE, CAST_USER_ADDR_T(imgp->ip_strings), imgp->ip_vfs_context);
- /* Initialize the common data in the image_params structure */
- bzero(imgp, sizeof(*imgp));
- imgp->ip_user_fname = uap->fname;
- imgp->ip_user_argv = uap->argp;
- imgp->ip_user_envv = uap->envp;
- imgp->ip_vattr = &va;
- imgp->ip_origvattr = &origva;
- imgp->ip_vfs_context = &context;
- imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT : IMGPF_NONE);
- imgp->ip_tws_cache_name = NULL;
- imgp->ip_p_comm = alt_p_comm; /* for PowerPC */
+again:
+ error = namei(&nd);
+ if (error)
+ goto bad_notrans;
+ imgp->ip_ndp = &nd; /* successful namei(); call nameidone() later */
+ imgp->ip_vp = nd.ni_vp; /* if set, need to vnode_put() at some point */
/*
- * XXXAUDIT: Currently, we only audit the pathname of the binary.
- * There may also be poor interaction with dyld.
- */
+ * Before we start the transition from binary A to binary B, make
+ * sure another thread hasn't started exiting the process. We grab
+ * the proc lock to check p_lflag initially, and the transition
+ * mechanism ensures that the value doesn't change after we release
+ * the lock.
+ */
+ proc_lock(p);
+ if (p->p_lflag & P_LEXIT) {
+ proc_unlock(p);
+ goto bad_notrans;
+ }
+ error = proc_transstart(p, 1);
+ proc_unlock(p);
+ if (error)
+ goto bad_notrans;
- task = current_task();
+ error = exec_check_permissions(imgp);
+ if (error)
+ goto bad;
+
+ /* Copy; avoid invocation of an interpreter overwriting the original */
+ if (once) {
+ once = 0;
+ *imgp->ip_origvattr = *imgp->ip_vattr;
+ }
+
+ error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
+ UIO_SYSSPACE, IO_NODELOCKED,
+ vfs_context_ucred(imgp->ip_vfs_context),
+ &resid, vfs_context_proc(imgp->ip_vfs_context));
+ if (error)
+ goto bad;
+
+encapsulated_binary:
+ /* Limit the number of iterations we will attempt on each binary */
+ if (--iterlimit == 0) {
+ error = EBADEXEC;
+ goto bad;
+ }
+ error = -1;
+ for(i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
+
+ error = (*execsw[i].ex_imgact)(imgp);
+
+ switch (error) {
+ /* case -1: not claimed: continue */
+ case -2: /* Encapsulated binary */
+ goto encapsulated_binary;
+
+ case -3: /* Interpreter */
+#if CONFIG_MACF
+ /*
+ * Copy the script label for later use. Note that
+ * the label can be different when the script is
+ * actually read by the interpreter.
+ */
+ if (imgp->ip_scriptlabelp)
+ mac_vnode_label_free(imgp->ip_scriptlabelp);
+ imgp->ip_scriptlabelp = mac_vnode_label_alloc();
+ if (imgp->ip_scriptlabelp == NULL) {
+ error = ENOMEM;
+ break;
+ }
+ mac_vnode_label_copy(imgp->ip_vp->v_label,
+ imgp->ip_scriptlabelp);
+#endif
+
+ nameidone(&nd);
+
+ vnode_put(imgp->ip_vp);
+ imgp->ip_vp = NULL; /* already put */
+ imgp->ip_ndp = NULL; /* already nameidone */
+
+ /* Use imgp->ip_strings, which exec_shell_imgact reset to the interpreter */
+ NDINIT(&nd, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
+ UIO_SYSSPACE, CAST_USER_ADDR_T(imgp->ip_strings), imgp->ip_vfs_context);
+
+#ifdef IMGPF_POWERPC
+ /*
+ * PowerPC does not follow symlinks because the
+ * code which sets exec_archhandler_ppc.fsid and
+ * exec_archhandler_ppc.fileid doesn't follow them.
+ */
+ if (imgp->ip_flags & IMGPF_POWERPC)
+ nd.ni_cnd.cn_flags &= ~FOLLOW;
+#endif /* IMGPF_POWERPC */
+
+ proc_transend(p, 0);
+ goto again;
+
+ default:
+ break;
+ }
+ }
+
+ /*
+ * Call out to allow 3rd party notification of exec.
+ * Ignore result of kauth_authorize_fileop call.
+ */
+ if (error == 0 && kauth_authorize_fileop_has_listeners()) {
+ kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
+ KAUTH_FILEOP_EXEC,
+ (uintptr_t)nd.ni_vp, 0);
+ }
+
+bad:
+ proc_transend(p, 0);
+
+bad_notrans:
+ if (imgp->ip_strings)
+ execargs_free(imgp);
+ if (imgp->ip_ndp)
+ nameidone(imgp->ip_ndp);
+
+ return (error);
+}
+
+/*
+ * exec_handle_port_actions
+ *
+ * Description: Go through the _posix_port_actions_t contents,
+ * calling task_set_special_port, task_set_exception_ports
+ * and/or audit_session_spawnjoin for the current task.
+ *
+ * Parameters: struct image_params * Image parameter block
+ * short psa_flags posix spawn attribute flags
+ *
+ * Returns: 0 Success
+ * EINVAL Failure
+ * ENOTSUP Illegal posix_spawn attr flag was set
+ */
+static errno_t
+exec_handle_port_actions(struct image_params *imgp, short psa_flags)
+{
+ _posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
+ _ps_port_action_t *act = NULL;
+ task_t task = p->task;
+ ipc_port_t port = NULL;
+ errno_t ret = KERN_SUCCESS;
+ int i;
+
+ for (i = 0; i < pacts->pspa_count; i++) {
+ act = &pacts->pspa_actions[i];
+
+ if (ipc_object_copyin(get_task_ipcspace(current_task()),
+ CAST_MACH_PORT_TO_NAME(act->new_port),
+ MACH_MSG_TYPE_COPY_SEND,
+ (ipc_object_t *) &port) != KERN_SUCCESS)
+ return EINVAL;
+
+ if (ret)
+ return ret;
+
+ switch (act->port_type) {
+ case PSPA_SPECIAL:
+ /* Only allowed when not under vfork */
+ if (!(psa_flags & POSIX_SPAWN_SETEXEC))
+ return ENOTSUP;
+ ret = (task_set_special_port(task,
+ act->which,
+ port) == KERN_SUCCESS) ? 0 : EINVAL;
+ break;
+ case PSPA_EXCEPTION:
+ /* Only allowed when not under vfork */
+ if (!(psa_flags & POSIX_SPAWN_SETEXEC))
+ return ENOTSUP;
+ ret = (task_set_exception_ports(task,
+ act->mask,
+ port,
+ act->behavior,
+ act->flavor) == KERN_SUCCESS) ? 0 : EINVAL;
+ break;
+#if CONFIG_AUDIT
+ case PSPA_AU_SESSION:
+ ret = audit_session_spawnjoin(p,
+ port);
+ break;
+#endif
+ default:
+ ret = EINVAL;
+ }
+ /* action failed, so release port resources */
+ if (ret) {
+ ipc_port_release_send(port);
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * exec_handle_file_actions
+ *
+ * Description: Go through the _posix_file_actions_t contents applying the
+ * open, close, and dup2 operations to the open file table for
+ * the current process.
+ *
+ * Parameters: struct image_params * Image parameter block
+ *
+ * Returns: 0 Success
+ * ???
+ *
+ * Note: Actions are applied in the order specified, with the credential
+ * of the parent process. This is done to permit the parent
+ * process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
+ * the child following operations the child may in fact not be
+ * normally permitted to perform.
+ */
+static int
+exec_handle_file_actions(struct image_params *imgp, short psa_flags)
+{
+ int error = 0;
+ int action;
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
+ _posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
+ int ival[2]; /* dummy retval for system calls) */
+
+ for (action = 0; action < px_sfap->psfa_act_count; action++) {
+ _psfa_action_t *psfa = &px_sfap->psfa_act_acts[ action];
+
+ switch(psfa->psfaa_type) {
+ case PSFA_OPEN: {
+ /*
+ * Open is different, in that it requires the use of
+ * a path argument, which is normally copied in from
+ * user space; because of this, we have to support an
+ * open from kernel space that passes an address space
+ * context of UIO_SYSSPACE, and casts the address
+ * argument to a user_addr_t.
+ */
+ struct vnode_attr va;
+ struct nameidata nd;
+ int mode = psfa->psfaa_openargs.psfao_mode;
+ struct dup2_args dup2a;
+ struct close_nocancel_args ca;
+ int origfd;
+
+ VATTR_INIT(&va);
+ /* Mask off all but regular access permissions */
+ mode = ((mode &~ p->p_fd->fd_cmask) & ALLPERMS) & ~S_ISTXT;
+ VATTR_SET(&va, va_mode, mode & ACCESSPERMS);
+
+ NDINIT(&nd, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
+ CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
+ imgp->ip_vfs_context);
+
+ error = open1(imgp->ip_vfs_context,
+ &nd,
+ psfa->psfaa_openargs.psfao_oflag,
+ &va,
+ ival);
+
+ /*
+ * If there's an error, or we get the right fd by
+ * accident, then drop out here. This is easier than
+ * reworking all the open code to preallocate fd
+ * slots, and internally taking one as an argument.
+ */
+ if (error || ival[0] == psfa->psfaa_filedes)
+ break;
+
+ origfd = ival[0];
+ /*
+ * If we didn't fall out from an error, we ended up
+ * with the wrong fd; so now we've got to try to dup2
+ * it to the right one.
+ */
+ dup2a.from = origfd;
+ dup2a.to = psfa->psfaa_filedes;
+
+ /*
+ * The dup2() system call implementation sets
+ * ival to newfd in the success case, but we
+ * can ignore that, since if we didn't get the
+ * fd we wanted, the error will stop us.
+ */
+ error = dup2(p, &dup2a, ival);
+ if (error)
+ break;
+
+ /*
+ * Finally, close the original fd.
+ */
+ ca.fd = origfd;
+
+ error = close_nocancel(p, &ca, ival);
+ }
+ break;
+
+ case PSFA_DUP2: {
+ struct dup2_args dup2a;
+
+ dup2a.from = psfa->psfaa_filedes;
+ dup2a.to = psfa->psfaa_openargs.psfao_oflag;
+
+ /*
+ * The dup2() system call implementation sets
+ * ival to newfd in the success case, but we
+ * can ignore that, since if we didn't get the
+ * fd we wanted, the error will stop us.
+ */
+ error = dup2(p, &dup2a, ival);
+ }
+ break;
+
+ case PSFA_CLOSE: {
+ struct close_nocancel_args ca;
+
+ ca.fd = psfa->psfaa_filedes;
+
+ error = close_nocancel(p, &ca, ival);
+ }
+ break;
+
+ case PSFA_INHERIT: {
+ struct fileproc *fp;
+ int fd = psfa->psfaa_filedes;
+
+ /*
+ * Check to see if the descriptor exists, and
+ * ensure it's -not- marked as close-on-exec.
+ * [Less code than the equivalent F_GETFD/F_SETFD.]
+ */
+ proc_fdlock(p);
+ if ((error = fp_lookup(p, fd, &fp, 1)) == 0) {
+ *fdflags(p, fd) &= ~UF_EXCLOSE;
+ (void) fp_drop(p, fd, fp, 1);
+ }
+ proc_fdunlock(p);
+ }
+ break;
+
+ default:
+ error = EINVAL;
+ break;
+ }
+
+ /* All file actions failures are considered fatal, per POSIX */
+
+ if (error)
+ break;
+ }
+
+ if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0)
+ return (error);
+
+ /*
+ * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
+ * this spawn only) as if "close on exec" is the default
+ * disposition of all pre-existing file descriptors. In this case,
+ * the list of file descriptors mentioned in the file actions
+ * are the only ones that can be inherited, so mark them now.
+ *
+ * The actual closing part comes later, in fdexec().
+ */
+ proc_fdlock(p);
+ for (action = 0; action < px_sfap->psfa_act_count; action++) {
+ _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
+ int fd = psfa->psfaa_filedes;
+
+ switch (psfa->psfaa_type) {
+ case PSFA_DUP2:
+ fd = psfa->psfaa_openargs.psfao_oflag;
+ /*FALLTHROUGH*/
+ case PSFA_OPEN:
+ case PSFA_INHERIT:
+ *fdflags(p, fd) |= UF_INHERIT;
+ break;
+
+ case PSFA_CLOSE:
+ break;
+ }
+ }
+ proc_fdunlock(p);
+
+ return (0);
+}
+
+
+/*
+ * posix_spawn
+ *
+ * Parameters: uap->pid Pointer to pid return area
+ * uap->fname File name to exec
+ * uap->argp Argument list
+ * uap->envp Environment list
+ *
+ * Returns: 0 Success
+ * EINVAL Invalid argument
+ * ENOTSUP Not supported
+ * ENOEXEC Executable file format error
+ * exec_activate_image:EINVAL Invalid argument
+ * exec_activate_image:EACCES Permission denied
+ * exec_activate_image:EINTR Interrupted function
+ * exec_activate_image:ENOMEM Not enough space
+ * exec_activate_image:EFAULT Bad address
+ * exec_activate_image:ENAMETOOLONG Filename too long
+ * exec_activate_image:ENOEXEC Executable file format error
+ * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
+ * exec_activate_image:EBADEXEC The executable is corrupt/unknown
+ * exec_activate_image:???
+ * mac_execve_enter:???
+ *
+ * TODO: Expect to need __mac_posix_spawn() at some point...
+ * Handle posix_spawnattr_t
+ * Handle posix_spawn_file_actions_t
+ */
+int
+posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
+{
+ proc_t p = ap; /* quiet bogus GCC vfork() warning */
+ user_addr_t pid = uap->pid;
+ int ival[2]; /* dummy retval for setpgid() */
+ char *bufp = NULL;
+ struct image_params *imgp;
+ struct vnode_attr *vap;
+ struct vnode_attr *origvap;
+ struct uthread *uthread = 0; /* compiler complains if not set to 0*/
+ int error, sig;
+ char alt_p_comm[sizeof(p->p_comm)] = {0}; /* for PowerPC */
+ int is_64 = IS_64BIT_PROCESS(p);
+ struct vfs_context context;
+ struct user__posix_spawn_args_desc px_args;
+ struct _posix_spawnattr px_sa;
+ _posix_spawn_file_actions_t px_sfap = NULL;
+ _posix_spawn_port_actions_t px_spap = NULL;
+ struct __kern_sigaction vec;
+ boolean_t spawn_no_exec = FALSE;
+ boolean_t proc_transit_set = TRUE;
+ boolean_t exec_done = FALSE;
+
+ /*
+ * Allocate a big chunk for locals instead of using stack since these
+ * structures are pretty big.
+ */
+ MALLOC(bufp, char *, (sizeof(*imgp) + sizeof(*vap) + sizeof(*origvap)), M_TEMP, M_WAITOK | M_ZERO);
+ imgp = (struct image_params *) bufp;
+ if (bufp == NULL) {
+ error = ENOMEM;
+ goto bad;
+ }
+ vap = (struct vnode_attr *) (bufp + sizeof(*imgp));
+ origvap = (struct vnode_attr *) (bufp + sizeof(*imgp) + sizeof(*vap));
+
+ /* Initialize the common data in the image_params structure */
+ imgp->ip_user_fname = uap->path;
+ imgp->ip_user_argv = uap->argv;
+ imgp->ip_user_envv = uap->envp;
+ imgp->ip_vattr = vap;
+ imgp->ip_origvattr = origvap;
+ imgp->ip_vfs_context = &context;
+ imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT : IMGPF_NONE);
+ imgp->ip_p_comm = alt_p_comm; /* for PowerPC */
+ imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
+
+ if (uap->adesc != USER_ADDR_NULL) {
+ if(is_64) {
+ error = copyin(uap->adesc, &px_args, sizeof(px_args));
+ } else {
+ struct user32__posix_spawn_args_desc px_args32;
+
+ error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
+
+ /*
+ * Convert arguments descriptor from external 32 bit
+ * representation to internal 64 bit representation
+ */
+ px_args.attr_size = px_args32.attr_size;
+ px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
+ px_args.file_actions_size = px_args32.file_actions_size;
+ px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
+ px_args.port_actions_size = px_args32.port_actions_size;
+ px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
+ }
+ if (error)
+ goto bad;
+
+ if (px_args.attr_size != 0) {
+ /*
+ * This could lose some of the port_actions pointer,
+ * but we already have it from px_args.
+ */
+ if ((error = copyin(px_args.attrp, &px_sa, sizeof(px_sa))) != 0)
+ goto bad;
+
+ imgp->ip_px_sa = &px_sa;
+ }
+ if (px_args.file_actions_size != 0) {
+ /* Limit file_actions to allowed number of open files */
+ int maxfa = (p->p_limit ? p->p_rlimit[RLIMIT_NOFILE].rlim_cur : NOFILE);
+ if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
+ px_args.file_actions_size > PSF_ACTIONS_SIZE(maxfa)) {
+ error = EINVAL;
+ goto bad;
+ }
+ MALLOC(px_sfap, _posix_spawn_file_actions_t, px_args.file_actions_size, M_TEMP, M_WAITOK);
+ if (px_sfap == NULL) {
+ error = ENOMEM;
+ goto bad;
+ }
+ imgp->ip_px_sfa = px_sfap;
+
+ if ((error = copyin(px_args.file_actions, px_sfap,
+ px_args.file_actions_size)) != 0)
+ goto bad;
+ }
+ if (px_args.port_actions_size != 0) {
+ /* Limit port_actions to one page of data */
+ if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
+ px_args.port_actions_size > PAGE_SIZE) {
+ error = EINVAL;
+ goto bad;
+ }
+
+ MALLOC(px_spap, _posix_spawn_port_actions_t,
+ px_args.port_actions_size, M_TEMP, M_WAITOK);
+ if (px_spap == NULL) {
+ error = ENOMEM;
+ goto bad;
+ }
+ imgp->ip_px_spa = px_spap;
+
+ if ((error = copyin(px_args.port_actions, px_spap,
+ px_args.port_actions_size)) != 0)
+ goto bad;
+ }
+ }
+
+ /* set uthread to parent */
uthread = get_bsdthread_info(current_thread());
+ /*
+ * <rdar://6640530>; this does not result in a behaviour change
+ * relative to Leopard, so there should not be any existing code
+ * which depends on it.
+ */
if (uthread->uu_flag & UT_VFORK) {
- vfexec = 1; /* Mark in exec */
- } else {
- if (task != kernel_task) {
- numthreads = get_task_numacts(task);
- if (numthreads <= 0 ) {
- kauth_cred_unref(&cred);
- return(EINVAL);
+ error = EINVAL;
+ goto bad;
+ }
+
+ /*
+ * If we don't have the extension flag that turns "posix_spawn()"
+ * into "execve() with options", then we will be creating a new
+ * process which does not inherit memory from the parent process,
+ * which is one of the most expensive things about using fork()
+ * and execve().
+ */
+ if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)){
+ if ((error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN)) != 0)
+ goto bad;
+ imgp->ip_flags |= IMGPF_SPAWN; /* spawn w/o exec */
+ spawn_no_exec = TRUE; /* used in later tests */
+ }
+
+ if (spawn_no_exec)
+ p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
+ assert(p != NULL);
+
+ /* By default, the thread everyone plays with is the parent */
+ context.vc_thread = current_thread();
+ context.vc_ucred = p->p_ucred; /* XXX must NOT be kauth_cred_get() */
+
+ /*
+ * However, if we're not in the setexec case, redirect the context
+ * to the newly created process instead
+ */
+ if (spawn_no_exec)
+ context.vc_thread = imgp->ip_new_thread;
+
+ /*
+ * Post fdcopy(), pre exec_handle_sugid() - this is where we want
+ * to handle the file_actions. Since vfork() also ends up setting
+ * us into the parent process group, and saved off the signal flags,
+ * this is also where we want to handle the spawn flags.
+ */
+
+ /* Has spawn file actions? */
+ if (imgp->ip_px_sfa != NULL) {
+ /*
+ * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
+ * is handled in exec_handle_file_actions().
+ */
+ if ((error = exec_handle_file_actions(imgp,
+ imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0)) != 0)
+ goto bad;
+ }
+
+ /* Has spawn port actions? */
+ if (imgp->ip_px_spa != NULL) {
+ /*
+ * The check for the POSIX_SPAWN_SETEXEC flag is done in
+ * exec_handle_port_actions().
+ */
+ if ((error = exec_handle_port_actions(imgp,
+ imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0)) != 0)
+ goto bad;
+ }
+
+ /* Has spawn attr? */
+ if (imgp->ip_px_sa != NULL) {
+ /*
+ * Set the process group ID of the child process; this has
+ * to happen before the image activation.
+ */
+ if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
+ struct setpgid_args spga;
+ spga.pid = p->p_pid;
+ spga.pgid = px_sa.psa_pgroup;
+ /*
+ * Effectively, call setpgid() system call; works
+ * because there are no pointer arguments.
+ */
+ if((error = setpgid(p, &spga, ival)) != 0)
+ goto bad;
+ }
+
+ /*
+ * Reset UID/GID to parent's RUID/RGID; This works only
+ * because the operation occurs *after* the vfork() and
+ * before the call to exec_handle_sugid() by the image
+ * activator called from exec_activate_image(). POSIX
+ * requires that any setuid/setgid bits on the process
+ * image will take precedence over the spawn attributes
+ * (re)setting them.
+ *
+ * The use of p_ucred is safe, since we are acting on the
+ * new process, and it has no threads other than the one
+ * we are creating for it.
+ */
+ if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
+ kauth_cred_t my_cred = p->p_ucred;
+ kauth_cred_t my_new_cred = kauth_cred_setuidgid(my_cred, kauth_cred_getruid(my_cred), kauth_cred_getrgid(my_cred));
+ if (my_new_cred != my_cred) {
+ p->p_ucred = my_new_cred;
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
}
- if (numthreads > 1) {
- kauth_cred_unref(&cred);
- return(ENOTSUP);
+ }
+
+ /*
+ * Disable ASLR for the spawned process.
+ */
+ if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR)
+ OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
+
+ /*
+ * Forcibly disallow execution from data pages for the spawned process
+ * even if it would otherwise be permitted by the architecture default.
+ */
+ if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC)
+ imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
+ }
+
+ /*
+ * Disable ASLR during image activation. This occurs either if the
+ * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
+ * P_DISABLE_ASLR was inherited from the parent process.
+ */
+ if (p->p_flag & P_DISABLE_ASLR)
+ imgp->ip_flags |= IMGPF_DISABLE_ASLR;
+
+ /*
+ * Clear transition flag so we won't hang if exec_activate_image() causes
+ * an automount (and launchd does a proc sysctl to service it).
+ *
+ * <rdar://problem/6848672>, <rdar://problem/5959568>.
+ */
+ if (spawn_no_exec) {
+ proc_transend(p, 0);
+ proc_transit_set = 0;
+ }
+
+#if MAC_SPAWN /* XXX */
+ if (uap->mac_p != USER_ADDR_NULL) {
+ error = mac_execve_enter(uap->mac_p, imgp);
+ if (error)
+ goto bad;
+ }
+#endif
+
+ /*
+ * Activate the image
+ */
+ error = exec_activate_image(imgp);
+
+ if (error == 0) {
+ /* process completed the exec */
+ exec_done = TRUE;
+ } else if (error == -1) {
+ /* Image not claimed by any activator? */
+ error = ENOEXEC;
+ }
+
+ /*
+ * If we have a spawn attr, and it contains signal related flags,
+ * the we need to process them in the "context" of the new child
+ * process, so we have to process it following image activation,
+ * prior to making the thread runnable in user space. This is
+ * necessitated by some signal information being per-thread rather
+ * than per-process, and we don't have the new allocation in hand
+ * until after the image is activated.
+ */
+ if (!error && imgp->ip_px_sa != NULL) {
+ thread_t child_thread = current_thread();
+ uthread_t child_uthread = uthread;
+
+ /*
+ * If we created a new child thread, then the thread and
+ * uthread are different than the current ones; otherwise,
+ * we leave them, since we are in the exec case instead.
+ */
+ if (spawn_no_exec) {
+ child_thread = imgp->ip_new_thread;
+ child_uthread = get_bsdthread_info(child_thread);
+ }
+
+ /*
+ * Mask a list of signals, instead of them being unmasked, if
+ * they were unmasked in the parent; note that some signals
+ * are not maskable.
+ */
+ if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK)
+ child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
+ /*
+ * Default a list of signals instead of ignoring them, if
+ * they were ignored in the parent. Note that we pass
+ * spawn_no_exec to setsigvec() to indicate that we called
+ * fork1() and therefore do not need to call proc_signalstart()
+ * internally.
+ */
+ if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
+ vec.sa_handler = SIG_DFL;
+ vec.sa_tramp = 0;
+ vec.sa_mask = 0;
+ vec.sa_flags = 0;
+ for (sig = 0; sig < NSIG; sig++)
+ if (px_sa.psa_sigdefault & (1 << sig)) {
+ error = setsigvec(p, child_thread, sig + 1, &vec, spawn_no_exec);
}
}
}
- error = execargs_alloc(imgp);
- if (error) {
- kauth_cred_unref(&cred);
- return(error);
+bad:
+ if (error == 0) {
+ /* upon successful spawn, re/set the proc control state */
+ if (imgp->ip_px_sa != NULL) {
+ switch (px_sa.psa_pcontrol) {
+ case POSIX_SPAWN_PCONTROL_THROTTLE:
+ p->p_pcaction = P_PCTHROTTLE;
+ break;
+ case POSIX_SPAWN_PCONTROL_SUSPEND:
+ p->p_pcaction = P_PCSUSP;
+ break;
+ case POSIX_SPAWN_PCONTROL_KILL:
+ p->p_pcaction = P_PCKILL;
+ break;
+ case POSIX_SPAWN_PCONTROL_NONE:
+ default:
+ p->p_pcaction = 0;
+ break;
+ };
+ }
+ exec_resettextvp(p, imgp);
}
+
/*
- * XXXAUDIT: Note: the double copyin introduces an audit
- * race. To correct this race, we must use a single
- * copyin(), e.g. by passing a flag to namei to indicate an
- * external path buffer is being used.
+ * If we successfully called fork1(), we always need to do this;
+ * we identify this case by noting the IMGPF_SPAWN flag. This is
+ * because we come back from that call with signals blocked in the
+ * child, and we have to unblock them, but we want to wait until
+ * after we've performed any spawn actions. This has to happen
+ * before check_for_signature(), which uses psignal.
*/
- error = exec_save_path(imgp, uap->fname, seg);
- if (error) {
- execargs_free(imgp);
- kauth_cred_unref(&cred);
- return(error);
+ if (spawn_no_exec) {
+ if (proc_transit_set)
+ proc_transend(p, 0);
+
+ /*
+ * Drop the signal lock on the child which was taken on our
+ * behalf by forkproc()/cloneproc() to prevent signals being
+ * received by the child in a partially constructed state.
+ */
+ proc_signalend(p, 0);
+
+ /* flag the 'fork' has occurred */
+ proc_knote(p->p_pptr, NOTE_FORK | p->p_pid);
+ /* then flag exec has occurred */
+ proc_knote(p, NOTE_EXEC);
+ DTRACE_PROC1(create, proc_t, p);
}
/*
- * No app profiles under chroot
- */
- if((p->p_fd->fd_rdir == NULLVP) && (app_profile != 0)) {
-
- /* grab the name of the file out of its path */
- /* we will need this for lookup within the */
- /* name file */
- /* Scan backwards for the first '/' or start of string */
- imgp->ip_tws_cache_name = imgp->ip_strendp;
- while (imgp->ip_tws_cache_name[0] != '/') {
- if(imgp->ip_tws_cache_name == imgp->ip_strings) {
- imgp->ip_tws_cache_name--;
- break;
- }
- imgp->ip_tws_cache_name--;
- }
- imgp->ip_tws_cache_name++;
- }
- NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
- seg, uap->fname, imgp->ip_vfs_context);
+ * We have to delay operations which might throw a signal until after
+ * the signals have been unblocked; however, we want that to happen
+ * after exec_resettextvp() so that the textvp is correct when they
+ * fire.
+ */
+ if (error == 0) {
+ error = check_for_signature(p, imgp);
-again:
- error = namei(&nd);
- if (error)
- goto bad;
- imgp->ip_ndp = &nd; /* successful namei(); call nameidone() later */
- imgp->ip_vp = nd.ni_vp; /* if set, need to vnode_put() at some point */
+ /*
+ * Pay for our earlier safety; deliver the delayed signals from
+ * the incomplete spawn process now that it's complete.
+ */
+ if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
+ psignal_vfork(p, p->task, imgp->ip_new_thread, SIGTRAP);
+ }
+ }
- error = exec_check_permissions(imgp);
- if (error)
- goto bad;
- /* Copy; avoid invocation of an interpreter overwriting the original */
- if (once) {
- once = 0;
- origva = va;
+ if (imgp != NULL) {
+ if (imgp->ip_vp)
+ vnode_put(imgp->ip_vp);
+ if (imgp->ip_strings)
+ execargs_free(imgp);
+ if (imgp->ip_px_sfa != NULL)
+ FREE(imgp->ip_px_sfa, M_TEMP);
+ if (imgp->ip_px_spa != NULL)
+ FREE(imgp->ip_px_spa, M_TEMP);
+
+#if CONFIG_MACF
+ if (imgp->ip_execlabelp)
+ mac_cred_label_free(imgp->ip_execlabelp);
+ if (imgp->ip_scriptlabelp)
+ mac_vnode_label_free(imgp->ip_scriptlabelp);
+#endif
+ }
+
+ if (error) {
+ DTRACE_PROC1(exec__failure, int, error);
+ } else {
+ /*
+ * <rdar://6609474> temporary - so dtrace call to current_proc()
+ * returns the child process instead of the parent.
+ */
+ if (imgp != NULL && imgp->ip_flags & IMGPF_SPAWN) {
+ p->p_lflag |= P_LINVFORK;
+ p->p_vforkact = current_thread();
+ uthread->uu_proc = p;
+ uthread->uu_flag |= UT_VFORK;
+ }
+
+ DTRACE_PROC(exec__success);
+
+ /*
+ * <rdar://6609474> temporary - so dtrace call to current_proc()
+ * returns the child process instead of the parent.
+ */
+ if (imgp != NULL && imgp->ip_flags & IMGPF_SPAWN) {
+ p->p_lflag &= ~P_LINVFORK;
+ p->p_vforkact = NULL;
+ uthread->uu_proc = PROC_NULL;
+ uthread->uu_flag &= ~UT_VFORK;
+ }
+ }
+
+ /* Return to both the parent and the child? */
+ if (imgp != NULL && spawn_no_exec) {
+ /*
+ * If the parent wants the pid, copy it out
+ */
+ if (pid != USER_ADDR_NULL)
+ (void)suword(pid, p->p_pid);
+ retval[0] = error;
+
+ /*
+ * If we had an error, perform an internal reap ; this is
+ * entirely safe, as we have a real process backing us.
+ */
+ if (error) {
+ proc_list_lock();
+ p->p_listflag |= P_LIST_DEADPARENT;
+ proc_list_unlock();
+ proc_lock(p);
+ /* make sure no one else has killed it off... */
+ if (p->p_stat != SZOMB && p->exit_thread == NULL) {
+ p->exit_thread = current_thread();
+ proc_unlock(p);
+ exit1(p, 1, (int *)NULL);
+ if (exec_done == FALSE) {
+ task_deallocate(get_threadtask(imgp->ip_new_thread));
+ thread_deallocate(imgp->ip_new_thread);
+ }
+ } else {
+ /* someone is doing it for us; just skip it */
+ proc_unlock(p);
+ }
+ } else {
+
+ /*
+ * Return" to the child
+ *
+ * Note: the image activator earlier dropped the
+ * task/thread references to the newly spawned
+ * process; this is OK, since we still have suspended
+ * queue references on them, so we should be fine
+ * with the delayed resume of the thread here.
+ */
+ (void)thread_resume(imgp->ip_new_thread);
+ }
}
+ if (bufp != NULL) {
+ FREE(bufp, M_TEMP);
+ }
+
+ return(error);
+}
- error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
- UIO_SYSSPACE32, IO_NODELOCKED, cred, &resid, p);
- if (error)
- goto bad;
-
-encapsulated_binary:
- error = -1;
- for(i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
- error = (*execsw[i].ex_imgact)(imgp);
+/*
+ * execve
+ *
+ * Parameters: uap->fname File name to exec
+ * uap->argp Argument list
+ * uap->envp Environment list
+ *
+ * Returns: 0 Success
+ * __mac_execve:EINVAL Invalid argument
+ * __mac_execve:ENOTSUP Invalid argument
+ * __mac_execve:EACCES Permission denied
+ * __mac_execve:EINTR Interrupted function
+ * __mac_execve:ENOMEM Not enough space
+ * __mac_execve:EFAULT Bad address
+ * __mac_execve:ENAMETOOLONG Filename too long
+ * __mac_execve:ENOEXEC Executable file format error
+ * __mac_execve:ETXTBSY Text file busy [misuse of error code]
+ * __mac_execve:???
+ *
+ * TODO: Dynamic linker header address on stack is copied via suword()
+ */
+/* ARGSUSED */
+int
+execve(proc_t p, struct execve_args *uap, int32_t *retval)
+{
+ struct __mac_execve_args muap;
+ int err;
- switch (error) {
- /* case -1: not claimed: continue */
- case -2: /* Encapsulated binary */
- goto encapsulated_binary;
+ muap.fname = uap->fname;
+ muap.argp = uap->argp;
+ muap.envp = uap->envp;
+ muap.mac_p = USER_ADDR_NULL;
+ err = __mac_execve(p, &muap, retval);
- case -3: /* Interpreter */
- vnode_put(imgp->ip_vp);
- imgp->ip_vp = NULL; /* already put */
- nd.ni_cnd.cn_nameiop = LOOKUP;
- nd.ni_cnd.cn_flags = (nd.ni_cnd.cn_flags & HASBUF) |
- (FOLLOW | LOCKLEAF);
+ return(err);
+}
-#ifdef IMGPF_POWERPC
- /*
- * PowerPC does not follow symlinks because the
- * code which sets exec_archhandler_ppc.fsid and
- * exec_archhandler_ppc.fileid doesn't follow them.
- */
- if (imgp->ip_flags & IMGPF_POWERPC)
- nd.ni_cnd.cn_flags &= ~FOLLOW;
-#endif /* IMGPF_POWERPC */
+/*
+ * __mac_execve
+ *
+ * Parameters: uap->fname File name to exec
+ * uap->argp Argument list
+ * uap->envp Environment list
+ * uap->mac_p MAC label supplied by caller
+ *
+ * Returns: 0 Success
+ * EINVAL Invalid argument
+ * ENOTSUP Not supported
+ * ENOEXEC Executable file format error
+ * exec_activate_image:EINVAL Invalid argument
+ * exec_activate_image:EACCES Permission denied
+ * exec_activate_image:EINTR Interrupted function
+ * exec_activate_image:ENOMEM Not enough space
+ * exec_activate_image:EFAULT Bad address
+ * exec_activate_image:ENAMETOOLONG Filename too long
+ * exec_activate_image:ENOEXEC Executable file format error
+ * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
+ * exec_activate_image:EBADEXEC The executable is corrupt/unknown
+ * exec_activate_image:???
+ * mac_execve_enter:???
+ *
+ * TODO: Dynamic linker header address on stack is copied via suword()
+ */
+int
+__mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval)
+{
+ char *bufp = NULL;
+ struct image_params *imgp;
+ struct vnode_attr *vap;
+ struct vnode_attr *origvap;
+ int error;
+ char alt_p_comm[sizeof(p->p_comm)] = {0}; /* for PowerPC */
+ int is_64 = IS_64BIT_PROCESS(p);
+ struct vfs_context context;
- nd.ni_segflg = UIO_SYSSPACE32;
- nd.ni_dirp = CAST_USER_ADDR_T(imgp->ip_interp_name);
- goto again;
+ context.vc_thread = current_thread();
+ context.vc_ucred = kauth_cred_proc_ref(p); /* XXX must NOT be kauth_cred_get() */
- default:
- break;
- }
+ /* Allocate a big chunk for locals instead of using stack since these
+ * structures a pretty big.
+ */
+ MALLOC(bufp, char *, (sizeof(*imgp) + sizeof(*vap) + sizeof(*origvap)), M_TEMP, M_WAITOK | M_ZERO);
+ imgp = (struct image_params *) bufp;
+ if (bufp == NULL) {
+ error = ENOMEM;
+ goto exit_with_error;
}
+ vap = (struct vnode_attr *) (bufp + sizeof(*imgp));
+ origvap = (struct vnode_attr *) (bufp + sizeof(*imgp) + sizeof(*vap));
- /* call out to allow 3rd party notification of exec.
- * Ignore result of kauth_authorize_fileop call.
- */
- if (error == 0 && kauth_authorize_fileop_has_listeners()) {
- kauth_authorize_fileop(vfs_context_ucred(&context), KAUTH_FILEOP_EXEC,
- (uintptr_t)nd.ni_vp, 0);
+ /* Initialize the common data in the image_params structure */
+ imgp->ip_user_fname = uap->fname;
+ imgp->ip_user_argv = uap->argp;
+ imgp->ip_user_envv = uap->envp;
+ imgp->ip_vattr = vap;
+ imgp->ip_origvattr = origvap;
+ imgp->ip_vfs_context = &context;
+ imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
+ imgp->ip_p_comm = alt_p_comm; /* for PowerPC */
+ imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
+
+#if CONFIG_MACF
+ if (uap->mac_p != USER_ADDR_NULL) {
+ error = mac_execve_enter(uap->mac_p, imgp);
+ if (error) {
+ kauth_cred_unref(&context.vc_ucred);
+ goto exit_with_error;
+ }
}
+#endif
+
+ error = exec_activate_image(imgp);
+
+ kauth_cred_unref(&context.vc_ucred);
/* Image not claimed by any activator? */
if (error == -1)
error = ENOEXEC;
-bad:
- kauth_cred_unref(&cred);
-
- if (imgp->ip_ndp)
- nameidone(imgp->ip_ndp);
- if (imgp->ip_vp)
+ if (error == 0) {
+ exec_resettextvp(p, imgp);
+ error = check_for_signature(p, imgp);
+ }
+ if (imgp->ip_vp != NULLVP)
vnode_put(imgp->ip_vp);
if (imgp->ip_strings)
execargs_free(imgp);
- if (!error && vfexec) {
- vfork_return(current_thread(), p->p_pptr, p, retval);
- (void)thread_resume(imgp->ip_vfork_thread);
- return(0);
+#if CONFIG_MACF
+ if (imgp->ip_execlabelp)
+ mac_cred_label_free(imgp->ip_execlabelp);
+ if (imgp->ip_scriptlabelp)
+ mac_vnode_label_free(imgp->ip_scriptlabelp);
+#endif
+ if (!error) {
+ struct uthread *uthread;
+
+ /* Sever any extant thread affinity */
+ thread_affinity_exec(current_thread());
+
+ DTRACE_PROC(exec__success);
+ uthread = get_bsdthread_info(current_thread());
+ if (uthread->uu_flag & UT_VFORK) {
+ vfork_return(p, retval, p->p_pid);
+ (void)thread_resume(imgp->ip_new_thread);
+ }
+ } else {
+ DTRACE_PROC1(exec__failure, int, error);
+ }
+
+exit_with_error:
+ if (bufp != NULL) {
+ FREE(bufp, M_TEMP);
}
+
return(error);
}
+/*
+ * copyinptr
+ *
+ * Description: Copy a pointer in from user space to a user_addr_t in kernel
+ * space, based on 32/64 bitness of the user space
+ *
+ * Parameters: froma User space address
+ * toptr Address of kernel space user_addr_t
+ * ptr_size 4/8, based on 'froma' address space
+ *
+ * Returns: 0 Success
+ * EFAULT Bad 'froma'
+ *
+ * Implicit returns:
+ * *ptr_size Modified
+ */
static int
copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
{
}
+/*
+ * copyoutptr
+ *
+ * Description: Copy a pointer out from a user_addr_t in kernel space to
+ * user space, based on 32/64 bitness of the user space
+ *
+ * Parameters: ua User space address to copy to
+ * ptr Address of kernel space user_addr_t
+ * ptr_size 4/8, based on 'ua' address space
+ *
+ * Returns: 0 Success
+ * EFAULT Bad 'ua'
+ *
+ */
static int
copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
{
if (ptr_size == 4) {
/* 64 bit value containing 32 bit address */
- unsigned int i = CAST_DOWN(unsigned int,ua); /* SAFE */
+ unsigned int i = CAST_DOWN_EXPLICIT(unsigned int,ua); /* SAFE */
error = copyout(&i, ptr, 4);
} else {
* Note: The strings segment layout is backward, from the beginning
* of the top of the stack to consume the minimal amount of
* space possible; the returned stack pointer points to the
- * end of the area consumed (stacks grow upward).
+ * end of the area consumed (stacks grow downward).
*
* argc is an int; arg[i] are pointers; env[i] are pointers;
- * exec_path is a pointer; the 0's are (void *)NULL's
+ * the 0's are (void *)NULL's
*
* The stack frame layout is:
*
- * +-------------+
- * sp-> | argc |
- * +-------------+
- * | arg[0] |
- * +-------------+
- * :
- * :
- * +-------------+
- * | arg[argc-1] |
- * +-------------+
- * | 0 |
- * +-------------+
- * | env[0] |
- * +-------------+
- * :
- * :
- * +-------------+
- * | env[n] |
- * +-------------+
- * | 0 |
- * +-------------+
- * | exec_path | In MacOS X PR2 Beaker2E the path passed to exec() is
- * +-------------+ passed on the stack just after the trailing 0 of the
- * | 0 | the envp[] array as a pointer to a string.
- * +-------------+
- * | PATH AREA |
- * +-------------+
- * | STRING AREA |
- * :
- * :
- * | | <- p->user_stack
- * +-------------+
+ * +-------------+ <- p->user_stack
+ * | 16b |
+ * +-------------+
+ * | STRING AREA |
+ * | : |
+ * | : |
+ * | : |
+ * +- -- -- -- --+
+ * | PATH AREA |
+ * +-------------+
+ * | 0 |
+ * +-------------+
+ * | applev[n] |
+ * +-------------+
+ * :
+ * :
+ * +-------------+
+ * | applev[1] |
+ * +-------------+
+ * | exec_path / |
+ * | applev[0] |
+ * +-------------+
+ * | 0 |
+ * +-------------+
+ * | env[n] |
+ * +-------------+
+ * :
+ * :
+ * +-------------+
+ * | env[0] |
+ * +-------------+
+ * | 0 |
+ * +-------------+
+ * | arg[argc-1] |
+ * +-------------+
+ * :
+ * :
+ * +-------------+
+ * | arg[0] |
+ * +-------------+
+ * | argc |
+ * sp-> +-------------+
*
* Although technically a part of the STRING AREA, we treat the PATH AREA as
* a separate entity. This allows us to align the beginning of the PATH AREA
* to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
* which preceed it on the stack are properly aligned.
- *
- * TODO: argc copied with suword(), which takes a 64 bit address
*/
+
static int
exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
{
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
- char *argv = imgp->ip_argv; /* modifiable copy of argv */
+ int ptr_area_size;
+ void *ptr_buffer_start, *ptr_buffer;
+ int string_size;
+
user_addr_t string_area; /* *argv[], *env[] */
- user_addr_t path_area; /* package launch path */
- user_addr_t ptr_area; /* argv[], env[], exec_path */
+ user_addr_t ptr_area; /* argv[], env[], applev[] */
+ user_addr_t argc_area; /* argc */
user_addr_t stack;
- int stringc = imgp->ip_argc + imgp->ip_envc;
- int len;
int error;
- int strspace;
+
+ unsigned i;
+ struct copyout_desc {
+ char *start_string;
+ int count;
+#if CONFIG_DTRACE
+ user_addr_t *dtrace_cookie;
+#endif
+ boolean_t null_term;
+ } descriptors[] = {
+ {
+ .start_string = imgp->ip_startargv,
+ .count = imgp->ip_argc,
+#if CONFIG_DTRACE
+ .dtrace_cookie = &p->p_dtrace_argv,
+#endif
+ .null_term = TRUE
+ },
+ {
+ .start_string = imgp->ip_endargv,
+ .count = imgp->ip_envc,
+#if CONFIG_DTRACE
+ .dtrace_cookie = &p->p_dtrace_envp,
+#endif
+ .null_term = TRUE
+ },
+ {
+ .start_string = imgp->ip_strings,
+ .count = 1,
+#if CONFIG_DTRACE
+ .dtrace_cookie = NULL,
+#endif
+ .null_term = FALSE
+ },
+ {
+ .start_string = imgp->ip_endenvv,
+ .count = imgp->ip_applec - 1, /* exec_path handled above */
+#if CONFIG_DTRACE
+ .dtrace_cookie = NULL,
+#endif
+ .null_term = TRUE
+ }
+ };
stack = *stackp;
- unsigned patharea_len = imgp->ip_argv - imgp->ip_strings;
- int envc_add = 0;
-
-#ifdef IMGPF_POWERPC
/*
- * oah750 expects /usr/lib/dyld\0 as the start of the program name.
- * It also expects to have a certain environment variable set to 0.
- * 50 bytes for each to ensure we have enough space without having
- * to count every byte.
- */
- char *progname, *envvar;
- char progname_str[] = "/usr/lib/dyld";
- char envvar_str[] = "OAH750_CFG_FU_STACK_SIZE=0";
-
- if (imgp->ip_flags & IMGPF_POWERPC) {
- progname = progname_str;
- envvar = envvar_str;
- patharea_len += strlen(progname) + strlen(envvar) + 2;
- envc_add = 1;
+ * All previous contributors to the string area
+ * should have aligned their sub-area
+ */
+ if (imgp->ip_strspace % ptr_size != 0) {
+ error = EINVAL;
+ goto bad;
}
-#endif /* IMGPF_POWERPC */
+
+ /* Grow the stack down for the strings we've been building up */
+ string_size = imgp->ip_strendp - imgp->ip_strings;
+ stack -= string_size;
+ string_area = stack;
+
/*
- * Set up pointers to the beginning of the string area, the beginning
- * of the path area, and the beginning of the pointer area (actually,
- * the location of argc, an int, which may be smaller than a pointer,
- * but we use ptr_size worth of space for it, for alignment).
+ * Need room for one pointer for each string, plus
+ * one for the NULLs terminating the argv, envv, and apple areas.
*/
- string_area = stack - (((imgp->ip_strendp - imgp->ip_strings) + ptr_size-1) & ~(ptr_size-1)) - ptr_size;
- path_area = string_area - ((patharea_len + ptr_size-1) & ~(ptr_size-1));
- ptr_area = path_area - ((imgp->ip_argc + imgp->ip_envc + 4 + envc_add) * ptr_size) - ptr_size /*argc*/;
+ ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) *
+ ptr_size;
+ stack -= ptr_area_size;
+ ptr_area = stack;
+
+ /* We'll construct all the pointer arrays in our string buffer,
+ * which we already know is aligned properly, and ip_argspace
+ * was used to verify we have enough space.
+ */
+ ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
- /* Return the initial stack address: the location of argc */
- *stackp = ptr_area;
+ /*
+ * Need room for pointer-aligned argc slot.
+ */
+ stack -= ptr_size;
+ argc_area = stack;
/*
* Record the size of the arguments area so that sysctl_procargs()
* can return the argument area without having to parse the arguments.
*/
+ proc_lock(p);
p->p_argc = imgp->ip_argc;
- p->p_argslen = (int)(stack - path_area);
+ p->p_argslen = (int)(*stackp - string_area);
+ proc_unlock(p);
+ /* Return the initial stack address: the location of argc */
+ *stackp = stack;
/*
- * Support for new app package launching for Mac OS X allocates
- * the "path" at the begining of the imgp->ip_strings buffer.
- * copy it just before the string area.
+ * Copy out the entire strings area.
*/
- len = 0;
-#ifdef IMGPF_POWERPC
- if (imgp->ip_flags & IMGPF_POWERPC) {
- error = copyoutstr(progname, path_area,
- patharea_len,
- (size_t *)&len);
- if (error)
- goto bad;
- error = copyoutstr(imgp->ip_strings, path_area + strlen(progname) + 1,
- patharea_len,
- (size_t *)&len);
- } else
-#endif /* IMGPF_POWERPC */
- error = copyoutstr(imgp->ip_strings, path_area,
- patharea_len,
- (size_t *)&len);
+ error = copyout(imgp->ip_strings, string_area,
+ string_size);
if (error)
goto bad;
+ for (i = 0; i < sizeof(descriptors)/sizeof(descriptors[0]); i++) {
+ char *cur_string = descriptors[i].start_string;
+ int j;
- /* Save a NULL pointer below it */
- (void)copyoutptr(0LL, path_area - ptr_size, ptr_size);
-
- /* Save the pointer to "path" just below it */
- (void)copyoutptr(path_area, path_area - 2*ptr_size, ptr_size);
-
- /*
- * ptr_size for 2 NULL one each ofter arg[argc -1] and env[n]
- * ptr_size for argc
- * skip over saved path, ptr_size for pointer to path,
- * and ptr_size for the NULL after pointer to path.
- */
-
- /* argc (int32, stored in a ptr_size area) */
- (void)suword(ptr_area, imgp->ip_argc);
- ptr_area += sizeof(int);
- /* pad to ptr_size, if 64 bit image, to ensure user stack alignment */
- if (imgp->ip_flags & IMGPF_IS_64BIT) {
- (void)suword(ptr_area, 0); /* int, not long: ignored */
- ptr_area += sizeof(int);
- }
+#if CONFIG_DTRACE
+ if (descriptors[i].dtrace_cookie) {
+ proc_lock(p);
+ *descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
+ proc_unlock(p);
+ }
+#endif /* CONFIG_DTRACE */
+ /*
+ * For each segment (argv, envv, applev), copy as many pointers as requested
+ * to our pointer buffer.
+ */
+ for (j = 0; j < descriptors[i].count; j++) {
+ user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
+
+ /* Copy out the pointer to the current string. Alignment has been verified */
+ if (ptr_size == 8) {
+ *(uint64_t *)ptr_buffer = (uint64_t)cur_address;
+ } else {
+ *(uint32_t *)ptr_buffer = (uint32_t)cur_address;
+ }
+
+ ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
+ cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
+ }
- /*
- * We use (string_area - path_area) here rather than the more
- * intuitive (imgp->ip_argv - imgp->ip_strings) because we are
- * interested in the length of the PATH_AREA in user space,
- * rather than the actual length of the execution path, since
- * it includes alignment padding of the PATH_AREA + STRING_AREA
- * to a ptr_size boundary.
- */
- strspace = SIZE_IMG_STRSPACE - (string_area - path_area);
- for (;;) {
- if (stringc == imgp->ip_envc) {
- /* argv[n] = NULL */
- (void)copyoutptr(0LL, ptr_area, ptr_size);
- ptr_area += ptr_size;
-#ifdef IMGPF_POWERPC
- if (envc_add) {
- (void)copyoutptr(string_area, ptr_area, ptr_size);
-
- do {
- if (strspace <= 0) {
- error = E2BIG;
- break;
- }
- error = copyoutstr(envvar, string_area,
- (unsigned)strspace,
- (size_t *)&len);
- string_area += len;
- envvar += len;
- strspace -= len;
- } while (error == ENAMETOOLONG);
- if (error == EFAULT || error == E2BIG)
- break;
- ptr_area += ptr_size;
+ if (descriptors[i].null_term) {
+ if (ptr_size == 8) {
+ *(uint64_t *)ptr_buffer = 0ULL;
+ } else {
+ *(uint32_t *)ptr_buffer = 0;
}
-#endif /* IMGPF_POWERPC */
+
+ ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
}
- if (--stringc < 0)
- break;
+ }
- /* pointer: argv[n]/env[n] */
- (void)copyoutptr(string_area, ptr_area, ptr_size);
+ /*
+ * Copy out all our pointer arrays in bulk.
+ */
+ error = copyout(ptr_buffer_start, ptr_area,
+ ptr_area_size);
+ if (error)
+ goto bad;
- /* string : argv[n][]/env[n][] */
- do {
- if (strspace <= 0) {
- error = E2BIG;
- break;
- }
- error = copyoutstr(argv, string_area,
- (unsigned)strspace,
- (size_t *)&len);
- string_area += len;
- argv += len;
- strspace -= len;
- } while (error == ENAMETOOLONG);
- if (error == EFAULT || error == E2BIG)
- break; /* bad stack - user's problem */
- ptr_area += ptr_size;
- }
- /* env[n] = NULL */
- (void)copyoutptr(0LL, ptr_area, ptr_size);
+ /* argc (int32, stored in a ptr_size area) */
+ error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
+ if (error)
+ goto bad;
bad:
return(error);
* Copy arguments and environment from user space into work area; we may
* have already copied some early arguments into the work area, and if
* so, any arguments opied in are appended to those already there.
+ * This function is the primary manipulator of ip_argspace, since
+ * these are the arguments the client of execve(2) knows about. After
+ * each argv[]/envv[] string is copied, we charge the string length
+ * and argv[]/envv[] pointer slot to ip_argspace, so that we can
+ * full preflight the arg list size.
*
* Parameters: struct image_params * the image parameter block
*
* Implicit returns;
* (imgp->ip_argc) Count of arguments, updated
* (imgp->ip_envc) Count of environment strings, updated
+ * (imgp->ip_argspace) Count of remaining of NCARGS
+ * (imgp->ip_interp_buffer) Interpreter and args (mutated in place)
*
*
- * Notes: The argument and environment vectors are user space pointers
+ * Note: The argument and environment vectors are user space pointers
* to arrays of user space pointers.
*/
static int
exec_extract_strings(struct image_params *imgp)
{
int error = 0;
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
- int seg = (IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32);
int ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT) ? 8 : 4;
+ int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
user_addr_t argv = imgp->ip_user_argv;
user_addr_t envv = imgp->ip_user_envv;
- /* Now, get rest of arguments */
+ /*
+ * Adjust space reserved for the path name by however much padding it
+ * needs. Doing this here since we didn't know if this would be a 32-
+ * or 64-bit process back in exec_save_path.
+ */
+ while (imgp->ip_strspace % new_ptr_size != 0) {
+ *imgp->ip_strendp++ = '\0';
+ imgp->ip_strspace--;
+ /* imgp->ip_argspace--; not counted towards exec args total */
+ }
/*
- * If we are running an interpreter, replace the av[0] that was
- * passed to execve() with the fully qualified path name that was
- * passed to execve() for interpreters which do not use the PATH
- * to locate their script arguments.
+ * From now on, we start attributing string space to ip_argspace
*/
- if((imgp->ip_flags & IMGPF_INTERPRET) != 0 && argv != 0LL) {
+ imgp->ip_startargv = imgp->ip_strendp;
+ imgp->ip_argc = 0;
+
+ if((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
user_addr_t arg;
+ char *argstart, *ch;
+
+ /* First, the arguments in the "#!" string are tokenized and extracted. */
+ argstart = imgp->ip_interp_buffer;
+ while (argstart) {
+ ch = argstart;
+ while (*ch && !IS_WHITESPACE(*ch)) {
+ ch++;
+ }
- error = copyinptr(argv, &arg, ptr_size);
- if (error)
- goto bad;
- if (arg != 0LL && arg != (user_addr_t)-1) {
- argv += ptr_size;
- error = exec_add_string(imgp, imgp->ip_user_fname, seg);
+ if (*ch == '\0') {
+ /* last argument, no need to NUL-terminate */
+ error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
+ argstart = NULL;
+ } else {
+ /* NUL-terminate */
+ *ch = '\0';
+ error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
+
+ /*
+ * Find the next string. We know spaces at the end of the string have already
+ * been stripped.
+ */
+ argstart = ch + 1;
+ while (IS_WHITESPACE(*argstart)) {
+ argstart++;
+ }
+ }
+
+ /* Error-check, regardless of whether this is the last interpreter arg or not */
if (error)
goto bad;
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
imgp->ip_argc++;
}
+
+ if (argv != 0LL) {
+ /*
+ * If we are running an interpreter, replace the av[0] that was
+ * passed to execve() with the path name that was
+ * passed to execve() for interpreters which do not use the PATH
+ * to locate their script arguments.
+ */
+ error = copyinptr(argv, &arg, ptr_size);
+ if (error)
+ goto bad;
+ if (arg != 0LL) {
+ argv += ptr_size; /* consume without using */
+ }
+ }
+
+ if (imgp->ip_interp_sugid_fd != -1) {
+ char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
+ snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
+ error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
+ } else {
+ error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
+ }
+
+ if (error)
+ goto bad;
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
+ imgp->ip_argc++;
}
while (argv != 0LL) {
if (error)
goto bad;
- argv += ptr_size;
if (arg == 0LL) {
break;
- } else if (arg == (user_addr_t)-1) {
- /* Um... why would it be -1? */
- error = EFAULT;
- goto bad;
}
+
+ argv += ptr_size;
+
/*
* av[n...] = arg[n]
*/
- error = exec_add_string(imgp, arg, seg);
+ error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
if (error)
goto bad;
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
imgp->ip_argc++;
}
+ /* Save space for argv[] NULL terminator */
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size;
+
+ /* Note where the args ends and env begins. */
+ imgp->ip_endargv = imgp->ip_strendp;
+ imgp->ip_envc = 0;
+
/* Now, get the environment */
while (envv != 0LL) {
user_addr_t env;
envv += ptr_size;
if (env == 0LL) {
break;
- } else if (env == (user_addr_t)-1) {
- error = EFAULT;
- goto bad;
}
/*
* av[n...] = env[n]
*/
- error = exec_add_string(imgp, env, seg);
+ error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
if (error)
goto bad;
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
imgp->ip_envc++;
}
+
+ /* Save space for envv[] NULL terminator */
+ if (imgp->ip_argspace < new_ptr_size) {
+ error = E2BIG;
+ goto bad;
+ }
+ imgp->ip_argspace -= new_ptr_size;
+
+ /* Align the tail of the combined argv+envv area */
+ while (imgp->ip_strspace % new_ptr_size != 0) {
+ if (imgp->ip_argspace < 1) {
+ error = E2BIG;
+ goto bad;
+ }
+ *imgp->ip_strendp++ = '\0';
+ imgp->ip_strspace--;
+ imgp->ip_argspace--;
+ }
+
+ /* Note where the envv ends and applev begins. */
+ imgp->ip_endenvv = imgp->ip_strendp;
+
+ /*
+ * From now on, we are no longer charging argument
+ * space to ip_argspace.
+ */
+
+bad:
+ return error;
+}
+
+static char *
+random_hex_str(char *str, int len)
+{
+ uint64_t low, high, value;
+ int idx;
+ char digit;
+
+ /* A 64-bit value will only take 16 characters, plus '0x' and NULL. */
+ if (len > 19)
+ len = 19;
+
+ /* We need enough room for at least 1 digit */
+ if (len < 4)
+ return (NULL);
+
+ low = random();
+ high = random();
+ value = high << 32 | low;
+
+ str[0] = '0';
+ str[1] = 'x';
+ for (idx = 2; idx < len - 1; idx++) {
+ digit = value & 0xf;
+ value = value >> 4;
+ if (digit < 10)
+ str[idx] = '0' + digit;
+ else
+ str[idx] = 'a' + (digit - 10);
+ }
+ str[idx] = '\0';
+ return (str);
+}
+
+/*
+ * Libc has an 8-element array set up for stack guard values. It only fills
+ * in one of those entries, and both gcc and llvm seem to use only a single
+ * 8-byte guard. Until somebody needs more than an 8-byte guard value, don't
+ * do the work to construct them.
+ */
+#define GUARD_VALUES 1
+#define GUARD_KEY "stack_guard="
+
+/*
+ * System malloc needs some entropy when it is initialized.
+ */
+#define ENTROPY_VALUES 2
+#define ENTROPY_KEY "malloc_entropy="
+
+/*
+ * Build up the contents of the apple[] string vector
+ */
+static int
+exec_add_apple_strings(struct image_params *imgp)
+{
+ int i, error;
+ int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT) ? 8 : 4;
+ char guard[19];
+ char guard_vec[strlen(GUARD_KEY) + 19 * GUARD_VALUES + 1];
+
+ char entropy[19];
+ char entropy_vec[strlen(ENTROPY_KEY) + 19 * ENTROPY_VALUES + 1];
+
+ /* exec_save_path stored the first string */
+ imgp->ip_applec = 1;
+
+ /*
+ * Supply libc with a collection of random values to use when
+ * implementing -fstack-protector.
+ */
+ (void)strlcpy(guard_vec, GUARD_KEY, sizeof (guard_vec));
+ for (i = 0; i < GUARD_VALUES; i++) {
+ random_hex_str(guard, sizeof (guard));
+ if (i)
+ (void)strlcat(guard_vec, ",", sizeof (guard_vec));
+ (void)strlcat(guard_vec, guard, sizeof (guard_vec));
+ }
+
+ error = exec_add_user_string(imgp, CAST_USER_ADDR_T(guard_vec), UIO_SYSSPACE, FALSE);
+ if (error)
+ goto bad;
+ imgp->ip_applec++;
+
+ /*
+ * Supply libc with entropy for system malloc.
+ */
+ (void)strlcpy(entropy_vec, ENTROPY_KEY, sizeof(entropy_vec));
+ for (i = 0; i < ENTROPY_VALUES; i++) {
+ random_hex_str(entropy, sizeof (entropy));
+ if (i)
+ (void)strlcat(entropy_vec, ",", sizeof (entropy_vec));
+ (void)strlcat(entropy_vec, entropy, sizeof (entropy_vec));
+ }
+
+ error = exec_add_user_string(imgp, CAST_USER_ADDR_T(entropy_vec), UIO_SYSSPACE, FALSE);
+ if (error)
+ goto bad;
+ imgp->ip_applec++;
+
+ /* Align the tail of the combined applev area */
+ while (imgp->ip_strspace % new_ptr_size != 0) {
+ *imgp->ip_strendp++ = '\0';
+ imgp->ip_strspace--;
+ }
+
bad:
return error;
}
-
#define unix_stack_size(p) (p->p_rlimit[RLIMIT_STACK].rlim_cur)
+/*
+ * exec_check_permissions
+ *
+ * Description: Verify that the file that is being attempted to be executed
+ * is in fact allowed to be executed based on it POSIX file
+ * permissions and other access control criteria
+ *
+ * Parameters: struct image_params * the image parameter block
+ *
+ * Returns: 0 Success
+ * EACCES Permission denied
+ * ENOEXEC Executable file format error
+ * ETXTBSY Text file busy [misuse of error code]
+ * vnode_getattr:???
+ * vnode_authorize:???
+ */
static int
exec_check_permissions(struct image_params *imgp)
{
struct vnode *vp = imgp->ip_vp;
struct vnode_attr *vap = imgp->ip_vattr;
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int error;
kauth_action_t action;
* will always succeed, and we don't want to happen unless the
* file really is executable.
*/
- if ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)
+ if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0))
return (EACCES);
/* Disallow zero length files */
imgp->ip_arch_size = vap->va_data_size;
/* Disable setuid-ness for traced programs or if MNT_NOSUID */
- if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_flag & P_TRACED))
+ if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED))
vap->va_mode &= ~(VSUID | VSGID);
+#if CONFIG_MACF
+ error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
+ if (error)
+ return (error);
+#endif
+
/* Check for execute permission */
action = KAUTH_VNODE_EXECUTE;
/* Traced images must also be readable */
- if (p->p_flag & P_TRACED)
+ if (p->p_lflag & P_LTRACED)
action |= KAUTH_VNODE_READ_DATA;
if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0)
return (error);
+#if 0
/* Don't let it run if anyone had it open for writing */
- if (vp->v_writecount)
+ vnode_lock(vp);
+ if (vp->v_writecount) {
+ panic("going to return ETXTBSY %x", vp);
+ vnode_unlock(vp);
return (ETXTBSY);
+ }
+ vnode_unlock(vp);
+#endif
+
#ifdef IMGPF_POWERPC
/*
* cached values, then we set the PowerPC environment flag.
*/
if (vap->va_fsid == exec_archhandler_ppc.fsid &&
- vap->va_fileid == (uint64_t)((u_long)exec_archhandler_ppc.fileid)) {
+ vap->va_fileid == exec_archhandler_ppc.fileid) {
imgp->ip_flags |= IMGPF_POWERPC;
}
#endif /* IMGPF_POWERPC */
return (error);
}
+
/*
* exec_handle_sugid
*
* Initially clear the P_SUGID in the process flags; if an SUGID process is
* exec'ing a non-SUGID image, then this is the point of no return.
*
- * If the image being activated is SUGI, then replace the credential with a
+ * If the image being activated is SUGID, then replace the credential with a
* copy, disable tracing (unless the tracing process is root), reset the
* mach task port to revoke it, set the P_SUGID bit,
*
exec_handle_sugid(struct image_params *imgp)
{
kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
- struct proc *p = vfs_context_proc(imgp->ip_vfs_context);
+ proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int i;
+ int leave_sugid_clear = 0;
int error = 0;
- static struct vnode *dev_null = NULLVP;
+#if CONFIG_MACF
+ int mac_transition;
+
+ /*
+ * Determine whether a call to update the MAC label will result in the
+ * credential changing.
+ *
+ * Note: MAC policies which do not actually end up modifying
+ * the label subsequently are strongly encouraged to
+ * return 0 for this check, since a non-zero answer will
+ * slow down the exec fast path for normal binaries.
+ */
+ mac_transition = mac_cred_check_label_update_execve(
+ imgp->ip_vfs_context,
+ imgp->ip_vp,
+ imgp->ip_scriptlabelp,
+ imgp->ip_execlabelp, p);
+#endif
- p->p_flag &= ~P_SUGID;
+ OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
+ /*
+ * Order of the following is important; group checks must go last,
+ * as we use the success of the 'ismember' check combined with the
+ * failure of the explicit match to indicate that we will be setting
+ * the egid of the process even though the new process did not
+ * require VSUID/VSGID bits in order for it to set the new group as
+ * its egid.
+ *
+ * Note: Technically, by this we are implying a call to
+ * setegid() in the new process, rather than implying
+ * it used its VSGID bit to set the effective group,
+ * even though there is no code in that process to make
+ * such a call.
+ */
if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
- cred->cr_gid != imgp->ip_origvattr->va_gid)) {
-#if KTRACE
- /*
- * If process is being ktraced, turn off - unless
- * root set it.
- */
- if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT)) {
- struct vnode *tvp = p->p_tracep;
- p->p_tracep = NULL;
- p->p_traceflag = 0;
- vnode_rele(tvp);
- }
+ ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
+ (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
+
+#if CONFIG_MACF
+/* label for MAC transition and neither VSUID nor VSGID */
+handle_mac_transition:
#endif
- /*
- * Replace the credential with a copy of itself if euid or egid change.
+
+ /*
+ * Replace the credential with a copy of itself if euid or
+ * egid change.
+ *
+ * Note: setuid binaries will automatically opt out of
+ * group resolver participation as a side effect
+ * of this operation. This is an intentional
+ * part of the security model, which requires a
+ * participating credential be established by
+ * escalating privilege, setting up all other
+ * aspects of the credential including whether
+ * or not to participate in external group
+ * membership resolution, then dropping their
+ * effective privilege to that of the desired
+ * final credential state.
*/
if (imgp->ip_origvattr->va_mode & VSUID) {
- p->p_ucred = kauth_cred_seteuid(p->p_ucred, imgp->ip_origvattr->va_uid);
+ p->p_ucred = kauth_cred_setresuid(p->p_ucred, KAUTH_UID_NONE, imgp->ip_origvattr->va_uid, imgp->ip_origvattr->va_uid, KAUTH_UID_NONE);
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
}
if (imgp->ip_origvattr->va_mode & VSGID) {
- p->p_ucred = kauth_cred_setegid(p->p_ucred, imgp->ip_origvattr->va_gid);
+ p->p_ucred = kauth_cred_setresgid(p->p_ucred, KAUTH_GID_NONE, imgp->ip_origvattr->va_gid, imgp->ip_origvattr->va_gid);
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
+ }
+
+#if CONFIG_MACF
+ /*
+ * If a policy has indicated that it will transition the label,
+ * before making the call into the MAC policies, get a new
+ * duplicate credential, so they can modify it without
+ * modifying any others sharing it.
+ */
+ if (mac_transition) {
+ kauth_cred_t my_cred;
+ if (kauth_proc_label_update_execve(p,
+ imgp->ip_vfs_context,
+ imgp->ip_vp,
+ imgp->ip_scriptlabelp,
+ imgp->ip_execlabelp)) {
+ /*
+ * If updating the MAC label resulted in a
+ * disjoint credential, flag that we need to
+ * set the P_SUGID bit. This protects
+ * against debuggers being attached by an
+ * insufficiently privileged process onto the
+ * result of a transition to a more privileged
+ * credential.
+ */
+ leave_sugid_clear = 0;
+ }
+
+ my_cred = kauth_cred_proc_ref(p);
+ mac_task_label_update_cred(my_cred, p->task);
+ kauth_cred_unref(&my_cred);
}
+#endif /* CONFIG_MACF */
/*
* Have mach reset the task and thread ports.
* a setuid exec to be able to access/control the
* task/thread after.
*/
- if (current_task() == p->task) {
- ipc_task_reset(p->task);
- ipc_thread_reset(current_thread());
- }
-
- p->p_flag |= P_SUGID;
-
- /* Cache the vnode for /dev/null the first time around */
- if (dev_null == NULLVP) {
- struct nameidata nd1;
-
- NDINIT(&nd1, LOOKUP, FOLLOW, UIO_SYSSPACE32,
- CAST_USER_ADDR_T("/dev/null"),
- imgp->ip_vfs_context);
+ ipc_task_reset(p->task);
+ ipc_thread_reset((imgp->ip_new_thread != NULL) ?
+ imgp->ip_new_thread : current_thread());
- if ((error = vn_open(&nd1, FREAD, 0)) == 0) {
- dev_null = nd1.ni_vp;
- /*
- * vn_open returns with both a use_count
- * and an io_count on the found vnode
- * drop the io_count, but keep the use_count
- */
- vnode_put(nd1.ni_vp);
- }
- }
+ /*
+ * If 'leave_sugid_clear' is non-zero, then we passed the
+ * VSUID and MACF checks, and successfully determined that
+ * the previous cred was a member of the VSGID group, but
+ * that it was not the default at the time of the execve,
+ * and that the post-labelling credential was not disjoint.
+ * So we don't set the P_SUGID on the basis of simply
+ * running this code.
+ */
+ if (!leave_sugid_clear)
+ OSBitOrAtomic(P_SUGID, &p->p_flag);
- /* Radar 2261856; setuid security hole fix */
- /* Patch from OpenBSD: A. Ramesh */
/*
+ * Radar 2261856; setuid security hole fix
* XXX For setuid processes, attempt to ensure that
* stdin, stdout, and stderr are already allocated.
* We do not want userland to accidentally allocate
* descriptors in this range which has implied meaning
* to libc.
*/
- if (dev_null != NULLVP) {
- for (i = 0; i < 3; i++) {
- struct fileproc *fp;
- int indx;
+ for (i = 0; i < 3; i++) {
+
+ if (p->p_fd->fd_ofiles[i] != NULL)
+ continue;
- if (p->p_fd->fd_ofiles[i] != NULL)
- continue;
+ /*
+ * Do the kernel equivalent of
+ *
+ * (void) open("/dev/null", O_RDONLY);
+ */
- if ((error = falloc(p, &fp, &indx)) != 0)
- continue;
+ struct fileproc *fp;
+ int indx;
- if ((error = vnode_ref_ext(dev_null, FREAD)) != 0) {
- fp_free(p, indx, fp);
- break;
- }
+ if ((error = falloc(p,
+ &fp, &indx, imgp->ip_vfs_context)) != 0)
+ continue;
+
+ struct nameidata nd1;
+
+ NDINIT(&nd1, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
+ CAST_USER_ADDR_T("/dev/null"),
+ imgp->ip_vfs_context);
- fp->f_fglob->fg_flag = FREAD;
- fp->f_fglob->fg_type = DTYPE_VNODE;
- fp->f_fglob->fg_ops = &vnops;
- fp->f_fglob->fg_data = (caddr_t)dev_null;
-
- proc_fdlock(p);
- procfdtbl_releasefd(p, indx, NULL);
- fp_drop(p, indx, fp, 1);
- proc_fdunlock(p);
+ if ((error = vn_open(&nd1, FREAD, 0)) != 0) {
+ fp_free(p, indx, fp);
+ break;
}
- /*
- * for now we need to drop the reference immediately
- * since we don't have any mechanism in place to
- * release it before starting to unmount "/dev"
- * during a reboot/shutdown
- */
- vnode_rele(dev_null);
- dev_null = NULLVP;
+
+ struct fileglob *fg = fp->f_fglob;
+
+ fg->fg_flag = FREAD;
+ fg->fg_type = DTYPE_VNODE;
+ fg->fg_ops = &vnops;
+ fg->fg_data = nd1.ni_vp;
+
+ vnode_put(nd1.ni_vp);
+
+ proc_fdlock(p);
+ procfdtbl_releasefd(p, indx, NULL);
+ fp_drop(p, indx, fp, 1);
+ proc_fdunlock(p);
}
}
+#if CONFIG_MACF
+ else {
+ /*
+ * We are here because we were told that the MAC label will
+ * be transitioned, and the binary is not VSUID or VSGID; to
+ * deal with this case, we could either duplicate a lot of
+ * code, or we can indicate we want to default the P_SUGID
+ * bit clear and jump back up.
+ */
+ if (mac_transition) {
+ leave_sugid_clear = 1;
+ goto handle_mac_transition;
+ }
+ }
+#endif /* CONFIG_MACF */
/*
* Implement the semantic where the effective user and group become
* the saved user and group in exec'ed programs.
*/
- p->p_ucred = kauth_cred_setsvuidgid(p->p_ucred, kauth_cred_getuid(p->p_ucred), p->p_ucred->cr_gid);
+ p->p_ucred = kauth_cred_setsvuidgid(p->p_ucred, kauth_cred_getuid(p->p_ucred), kauth_cred_getgid(p->p_ucred));
+ /* update cred on proc */
+ PROC_UPDATE_CREDS_ONPROC(p);
- /* XXX Obsolete; security token should not be separate from cred */
+ /* Update the process' identity version and set the security token */
+ p->p_idversion++;
set_security_token(p);
return(error);
}
+
+/*
+ * create_unix_stack
+ *
+ * Description: Set the user stack address for the process to the provided
+ * address. If a custom stack was not set as a result of the
+ * load process (i.e. as specified by the image file for the
+ * executable), then allocate the stack in the provided map and
+ * set up appropriate guard pages for enforcing administrative
+ * limits on stack growth, if they end up being needed.
+ *
+ * Parameters: p Process to set stack on
+ * user_stack Address to set stack for process to
+ * customstack FALSE if no custom stack in binary
+ * map Address map in which to allocate the
+ * new stack, if 'customstack' is FALSE
+ *
+ * Returns: KERN_SUCCESS Stack successfully created
+ * !KERN_SUCCESS Mach failure code
+ */
static kern_return_t
create_unix_stack(vm_map_t map, user_addr_t user_stack, int customstack,
- struct proc *p)
+ proc_t p)
{
- mach_vm_size_t size;
- mach_vm_offset_t addr;
+ mach_vm_size_t size, prot_size;
+ mach_vm_offset_t addr, prot_addr;
+ kern_return_t kr;
+ proc_lock(p);
p->user_stack = user_stack;
+ proc_unlock(p);
+
if (!customstack) {
- size = mach_vm_round_page(unix_stack_size(p));
+ /*
+ * Allocate enough space for the maximum stack size we
+ * will ever authorize and an extra page to act as
+ * a guard page for stack overflows.
+ */
+ size = mach_vm_round_page(MAXSSIZ);
+#if STACK_GROWTH_UP
+ addr = mach_vm_trunc_page(user_stack);
+#else /* STACK_GROWTH_UP */
addr = mach_vm_trunc_page(user_stack - size);
- return (mach_vm_allocate(map, &addr, size,
+#endif /* STACK_GROWTH_UP */
+ kr = mach_vm_allocate(map, &addr, size,
VM_MAKE_TAG(VM_MEMORY_STACK) |
- VM_FLAGS_FIXED));
- } else
- return(KERN_SUCCESS);
+ VM_FLAGS_FIXED);
+ if (kr != KERN_SUCCESS) {
+ return kr;
+ }
+ /*
+ * And prevent access to what's above the current stack
+ * size limit for this process.
+ */
+ prot_addr = addr;
+#if STACK_GROWTH_UP
+ prot_addr += unix_stack_size(p);
+#endif /* STACK_GROWTH_UP */
+ prot_addr = mach_vm_round_page(prot_addr);
+ prot_size = mach_vm_trunc_page(size - unix_stack_size(p));
+ kr = mach_vm_protect(map,
+ prot_addr,
+ prot_size,
+ FALSE,
+ VM_PROT_NONE);
+ if (kr != KERN_SUCCESS) {
+ (void) mach_vm_deallocate(map, addr, size);
+ return kr;
+ }
+ }
+ return KERN_SUCCESS;
}
#include <sys/reboot.h>
static char init_program_name[128] = "/sbin/launchd";
-static const char * other_init = "/sbin/mach_init";
-
-char init_args[128] = "";
struct execve_args init_exec_args;
-int init_attempts = 0;
-
+/*
+ * load_init_program
+ *
+ * Description: Load the "init" program; in most cases, this will be "launchd"
+ *
+ * Parameters: p Process to call execve() to create
+ * the "init" program
+ *
+ * Returns: (void)
+ *
+ * Notes: The process that is passed in is the first manufactured
+ * process on the system, and gets here via bsd_ast() firing
+ * for the first time. This is done to ensure that bsd_init()
+ * has run to completion.
+ */
void
-load_init_program(struct proc *p)
+load_init_program(proc_t p)
{
vm_offset_t init_addr;
- char *argv[3];
+ int argc = 0;
+ uint32_t argv[3];
int error;
- register_t retval[2];
-
- error = 0;
-
- /* init_args are copied in string form directly from bootstrap */
-
- do {
- if (boothowto & RB_INITNAME) {
- printf("init program? ");
-#if FIXME /* [ */
- gets(init_program_name, init_program_name);
-#endif /* FIXME ] */
- }
-
- if (error && ((boothowto & RB_INITNAME) == 0) &&
- (init_attempts == 1)) {
- printf("Load of %s, errno %d, trying %s\n",
- init_program_name, error, other_init);
- error = 0;
- bcopy(other_init, init_program_name,
- sizeof(other_init));
- }
-
- init_attempts++;
-
- if (error) {
- printf("Load of %s failed, errno %d\n",
- init_program_name, error);
- error = 0;
- boothowto |= RB_INITNAME;
- continue;
- }
+ int retval[2];
- /*
- * Copy out program name.
- */
+ /*
+ * Copy out program name.
+ */
- init_addr = VM_MIN_ADDRESS;
- (void) vm_allocate(current_map(), &init_addr,
- PAGE_SIZE, VM_FLAGS_ANYWHERE);
- if (init_addr == 0)
- init_addr++;
+ init_addr = VM_MIN_ADDRESS;
+ (void) vm_allocate(current_map(), &init_addr, PAGE_SIZE,
+ VM_FLAGS_ANYWHERE);
+ if (init_addr == 0)
+ init_addr++;
- (void) copyout((caddr_t) init_program_name,
- CAST_USER_ADDR_T(init_addr),
- (unsigned) sizeof(init_program_name)+1);
+ (void) copyout((caddr_t) init_program_name, CAST_USER_ADDR_T(init_addr),
+ (unsigned) sizeof(init_program_name)+1);
- argv[0] = (char *) init_addr;
- init_addr += sizeof(init_program_name);
- init_addr = (vm_offset_t)ROUND_PTR(char, init_addr);
+ argv[argc++] = (uint32_t)init_addr;
+ init_addr += sizeof(init_program_name);
+ init_addr = (vm_offset_t)ROUND_PTR(char, init_addr);
- /*
- * Put out first (and only) argument, similarly.
- * Assumes everything fits in a page as allocated
- * above.
- */
+ /*
+ * Put out first (and only) argument, similarly.
+ * Assumes everything fits in a page as allocated
+ * above.
+ */
+ if (boothowto & RB_SINGLE) {
+ const char *init_args = "-s";
- (void) copyout((caddr_t) init_args,
- CAST_USER_ADDR_T(init_addr),
- (unsigned) sizeof(init_args));
+ copyout(init_args, CAST_USER_ADDR_T(init_addr),
+ strlen(init_args));
- argv[1] = (char *) init_addr;
- init_addr += sizeof(init_args);
+ argv[argc++] = (uint32_t)init_addr;
+ init_addr += strlen(init_args);
init_addr = (vm_offset_t)ROUND_PTR(char, init_addr);
- /*
- * Null-end the argument list
- */
+ }
- argv[2] = (char *) 0;
-
- /*
- * Copy out the argument list.
- */
-
- (void) copyout((caddr_t) argv,
- CAST_USER_ADDR_T(init_addr),
- (unsigned) sizeof(argv));
+ /*
+ * Null-end the argument list
+ */
+ argv[argc] = 0;
+
+ /*
+ * Copy out the argument list.
+ */
+
+ (void) copyout((caddr_t) argv, CAST_USER_ADDR_T(init_addr),
+ (unsigned) sizeof(argv));
- /*
- * Set up argument block for fake call to execve.
- */
+ /*
+ * Set up argument block for fake call to execve.
+ */
- init_exec_args.fname = CAST_USER_ADDR_T(argv[0]);
- init_exec_args.argp = CAST_USER_ADDR_T((char **)init_addr);
- init_exec_args.envp = CAST_USER_ADDR_T(0);
-
- /* So that mach_init task
- * is set with uid,gid 0 token
- */
- set_security_token(p);
+ init_exec_args.fname = CAST_USER_ADDR_T(argv[0]);
+ init_exec_args.argp = CAST_USER_ADDR_T((char **)init_addr);
+ init_exec_args.envp = CAST_USER_ADDR_T(0);
+
+ /*
+ * So that mach_init task is set with uid,gid 0 token
+ */
+ set_security_token(p);
- error = execve(p,&init_exec_args,retval);
- } while (error);
+ error = execve(p,&init_exec_args,retval);
+ if (error)
+ panic("Process 1 exec of %s failed, errno %d",
+ init_program_name, error);
}
/*
- * Convert a load_return_t to an errno.
+ * load_return_to_errno
+ *
+ * Description: Convert a load_return_t (Mach error) to an errno (BSD error)
+ *
+ * Parameters: lrtn Mach error number
+ *
+ * Returns: (int) BSD error number
+ * 0 Success
+ * EBADARCH Bad architecture
+ * EBADMACHO Bad Mach object file
+ * ESHLIBVERS Bad shared library version
+ * ENOMEM Out of memory/resource shortage
+ * EACCES Access denied
+ * ENOENT Entry not found (usually "file does
+ * does not exist")
+ * EIO An I/O error occurred
+ * EBADEXEC The executable is corrupt/unknown
*/
static int
load_return_to_errno(load_return_t lrtn)
{
switch (lrtn) {
- case LOAD_SUCCESS:
- return 0;
- case LOAD_BADARCH:
- return EBADARCH;
- case LOAD_BADMACHO:
- return EBADMACHO;
- case LOAD_SHLIB:
- return ESHLIBVERS;
- case LOAD_NOSPACE:
- case LOAD_RESOURCE:
- return ENOMEM;
- case LOAD_PROTECT:
- return EACCES;
- case LOAD_ENOENT:
- return ENOENT;
- case LOAD_IOERROR:
- return EIO;
- case LOAD_FAILURE:
- default:
- return EBADEXEC;
+ case LOAD_SUCCESS:
+ return 0;
+ case LOAD_BADARCH:
+ return EBADARCH;
+ case LOAD_BADMACHO:
+ return EBADMACHO;
+ case LOAD_SHLIB:
+ return ESHLIBVERS;
+ case LOAD_NOSPACE:
+ case LOAD_RESOURCE:
+ return ENOMEM;
+ case LOAD_PROTECT:
+ return EACCES;
+ case LOAD_ENOENT:
+ return ENOENT;
+ case LOAD_IOERROR:
+ return EIO;
+ case LOAD_FAILURE:
+ default:
+ return EBADEXEC;
}
}
#include <kern/clock.h>
#include <mach/kern_return.h>
-extern semaphore_t execve_semaphore;
-
/*
- * The block of memory used by the execve arguments. At the same time,
- * we allocate a page so that we can read in the first page of the image.
+ * execargs_alloc
+ *
+ * Description: Allocate the block of memory used by the execve arguments.
+ * At the same time, we allocate a page so that we can read in
+ * the first page of the image.
+ *
+ * Parameters: struct image_params * the image parameter block
+ *
+ * Returns: 0 Success
+ * EINVAL Invalid argument
+ * EACCES Permission denied
+ * EINTR Interrupted function
+ * ENOMEM Not enough space
+ *
+ * Notes: This is a temporary allocation into the kernel address space
+ * to enable us to copy arguments in from user space. This is
+ * necessitated by not mapping the process calling execve() into
+ * the kernel address space during the execve() system call.
+ *
+ * We assemble the argument and environment, etc., into this
+ * region before copying it as a single block into the child
+ * process address space (at the top or bottom of the stack,
+ * depending on which way the stack grows; see the function
+ * exec_copyout_strings() for details).
+ *
+ * This ends up with a second (possibly unnecessary) copy compared
+ * with assembing the data directly into the child address space,
+ * instead, but since we cannot be guaranteed that the parent has
+ * not modified its environment, we can't really know that it's
+ * really a block there as well.
*/
+
+
+static int execargs_waiters = 0;
+lck_mtx_t *execargs_cache_lock;
+
+static void
+execargs_lock_lock(void) {
+ lck_mtx_lock_spin(execargs_cache_lock);
+}
+
+static void
+execargs_lock_unlock(void) {
+ lck_mtx_unlock(execargs_cache_lock);
+}
+
+static void
+execargs_lock_sleep(void) {
+ lck_mtx_sleep(execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_UNINT);
+}
+
+static kern_return_t
+execargs_purgeable_allocate(char **execarg_address) {
+ kern_return_t kr = vm_allocate(bsd_pageable_map, (vm_offset_t *)execarg_address, BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE);
+ assert(kr == KERN_SUCCESS);
+ return kr;
+}
+
+static kern_return_t
+execargs_purgeable_reference(void *execarg_address) {
+ int state = VM_PURGABLE_NONVOLATILE;
+ kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
+
+ assert(kr == KERN_SUCCESS);
+ return kr;
+}
+
+static kern_return_t
+execargs_purgeable_volatilize(void *execarg_address) {
+ int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
+ kern_return_t kr;
+ kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
+
+ assert(kr == KERN_SUCCESS);
+
+ return kr;
+}
+
+static void
+execargs_wakeup_waiters(void) {
+ thread_wakeup(&execargs_free_count);
+}
+
static int
execargs_alloc(struct image_params *imgp)
{
kern_return_t kret;
+ int i, cache_index = -1;
- kret = semaphore_wait(execve_semaphore);
- if (kret != KERN_SUCCESS)
- switch (kret) {
- default:
- return (EINVAL);
- case KERN_INVALID_ADDRESS:
- case KERN_PROTECTION_FAILURE:
- return (EACCES);
- case KERN_ABORTED:
- case KERN_OPERATION_TIMED_OUT:
- return (EINTR);
+ execargs_lock_lock();
+
+ while (execargs_free_count == 0) {
+ execargs_waiters++;
+ execargs_lock_sleep();
+ execargs_waiters--;
+ }
+
+ execargs_free_count--;
+
+ for (i = 0; i < execargs_cache_size; i++) {
+ vm_offset_t element = execargs_cache[i];
+ if (element) {
+ cache_index = i;
+ imgp->ip_strings = (char *)(execargs_cache[i]);
+ execargs_cache[i] = 0;
+ break;
}
+ }
+
+ assert(execargs_free_count >= 0);
+
+ execargs_lock_unlock();
+
+ if (cache_index == -1) {
+ kret = execargs_purgeable_allocate(&imgp->ip_strings);
+ }
+ else
+ kret = execargs_purgeable_reference(imgp->ip_strings);
- kret = kmem_alloc_pageable(bsd_pageable_map, (vm_offset_t *)&imgp->ip_strings, NCARGS + PAGE_SIZE);
- imgp->ip_vdata = imgp->ip_strings + NCARGS;
+ assert(kret == KERN_SUCCESS);
if (kret != KERN_SUCCESS) {
- semaphore_signal(execve_semaphore);
return (ENOMEM);
}
+
+ /* last page used to read in file headers */
+ imgp->ip_vdata = imgp->ip_strings + ( NCARGS + PAGE_SIZE );
+ imgp->ip_strendp = imgp->ip_strings;
+ imgp->ip_argspace = NCARGS;
+ imgp->ip_strspace = ( NCARGS + PAGE_SIZE );
+
return (0);
}
+/*
+ * execargs_free
+ *
+ * Description: Free the block of memory used by the execve arguments and the
+ * first page of the executable by a previous call to the function
+ * execargs_alloc().
+ *
+ * Parameters: struct image_params * the image parameter block
+ *
+ * Returns: 0 Success
+ * EINVAL Invalid argument
+ * EINTR Oeration interrupted
+ */
static int
execargs_free(struct image_params *imgp)
{
kern_return_t kret;
+ int i;
+ boolean_t needs_wakeup = FALSE;
+
+ kret = execargs_purgeable_volatilize(imgp->ip_strings);
- kmem_free(bsd_pageable_map, (vm_offset_t)imgp->ip_strings, NCARGS + PAGE_SIZE);
- imgp->ip_strings = NULL;
-
- kret = semaphore_signal(execve_semaphore);
- switch (kret) {
- case KERN_INVALID_ADDRESS:
- case KERN_PROTECTION_FAILURE:
- return (EINVAL);
- case KERN_ABORTED:
- case KERN_OPERATION_TIMED_OUT:
- return (EINTR);
- case KERN_SUCCESS:
- return(0);
- default:
- return (EINVAL);
+ execargs_lock_lock();
+ execargs_free_count++;
+
+ for (i = 0; i < execargs_cache_size; i++) {
+ vm_offset_t element = execargs_cache[i];
+ if (element == 0) {
+ execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
+ imgp->ip_strings = NULL;
+ break;
+ }
+ }
+
+ assert(imgp->ip_strings == NULL);
+
+ if (execargs_waiters > 0)
+ needs_wakeup = TRUE;
+
+ execargs_lock_unlock();
+
+ if (needs_wakeup == TRUE)
+ execargs_wakeup_waiters();
+
+ return ((kret == KERN_SUCCESS ? 0 : EINVAL));
+}
+
+static void
+exec_resettextvp(proc_t p, struct image_params *imgp)
+{
+ vnode_t vp;
+ off_t offset;
+ vnode_t tvp = p->p_textvp;
+ int ret;
+
+ vp = imgp->ip_vp;
+ offset = imgp->ip_arch_offset;
+
+ if (vp == NULLVP)
+ panic("exec_resettextvp: expected valid vp");
+
+ ret = vnode_ref(vp);
+ proc_lock(p);
+ if (ret == 0) {
+ p->p_textvp = vp;
+ p->p_textoff = offset;
+ } else {
+ p->p_textvp = NULLVP; /* this is paranoia */
+ p->p_textoff = 0;
+ }
+ proc_unlock(p);
+
+ if ( tvp != NULLVP) {
+ if (vnode_getwithref(tvp) == 0) {
+ vnode_rele(tvp);
+ vnode_put(tvp);
+ }
+ }
+
+}
+
+static int
+check_for_signature(proc_t p, struct image_params *imgp)
+{
+ void *blob = NULL;
+ size_t length = 0;
+ mach_port_t port = NULL;
+ kern_return_t kr = KERN_FAILURE;
+ int error = EACCES;
+ unsigned char hash[SHA1_RESULTLEN];
+
+ /*
+ * Override inherited code signing flags with the
+ * ones for the process that is being successfully
+ * loaded
+ */
+ proc_lock(p);
+ p->p_csflags = imgp->ip_csflags;
+ proc_unlock(p);
+
+ /* Set the switch_protect flag on the map */
+ if(p->p_csflags & (CS_HARD|CS_KILL)) {
+ vm_map_switch_protect(get_task_map(p->task), TRUE);
+ }
+
+ /* If the process is not signed or if it contains
+ * entitlements, we need to communicate through the
+ * task_access_port to taskgated. taskgated will provide a
+ * detached code signature if present, and will enforce any
+ * restrictions on entitlements. taskgated returns
+ * KERN_SUCCESS if it has completed its work and the exec
+ * should continue, or KERN_FAILURE if the exec should fail.
+ */
+ error = cs_entitlements_blob_get(p, &blob, &length);
+
+ /* if signed and no entitlements, then we're done here */
+ if ((p->p_csflags & CS_VALID) && NULL == blob) {
+ error = 0;
+ goto done;
+ }
+
+ kr = task_get_task_access_port(p->task, &port);
+ if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
+ error = 0;
+#if !CONFIG_EMBEDDED
+ /* fatal on the desktop when entitlements are present */
+ if (NULL != blob)
+ error = EACCES;
+#endif
+ goto done;
+ }
+
+ kr = find_code_signature(port, p->p_pid);
+ if (KERN_SUCCESS != kr) {
+ error = EACCES;
+ goto done;
}
+
+ /* Only do this if exec_resettextvp() did not fail */
+ if (p->p_textvp != NULLVP) {
+ /*
+ * If there's a new code directory, mark this process
+ * as signed.
+ */
+ if (0 == ubc_cs_getcdhash(p->p_textvp, p->p_textoff, hash)) {
+ proc_lock(p);
+ p->p_csflags |= CS_VALID;
+ proc_unlock(p);
+ }
+ }
+
+done:
+ if (0 != error)
+ /* make very sure execution fails */
+ psignal(p, SIGKILL);
+ return error;
}
+
projects / apple / xnu.git / blobdiff