xnu-4570.41.2.tar.gz

[apple/xnu.git] / bsd / kern / mach_process.c

diff --git a/bsd/kern/mach_process.c b/bsd/kern/mach_process.c
index b0cda592a03ded4966c738785efe612c6e31cfda..72d262defd0588bcda6e376288ea1107eaa1c2a1 100644 (file)
--- a/bsd/kern/mach_process.c
+++ b/bsd/kern/mach_process.c
@@ -95,6 +95,10 @@
 
 #include <pexpert/pexpert.h>
 
+#if CONFIG_MACF
+#include <security/mac_framework.h>
+#endif
+
 /* XXX ken/bsd_kern.c - prototype should be in common header */
 int get_task_userstop(task_t);
 
@@ -128,13 +132,17 @@ ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
        AUDIT_ARG(value32, uap->data);
 
        if (uap->req == PT_DENY_ATTACH) {
+#if (DEVELOPMENT || DEBUG) && CONFIG_EMBEDDED
+               if (PE_i_can_has_debugger(NULL))
+                       return(0);
+#endif
                proc_lock(p);
                if (ISSET(p->p_lflag, P_LTRACED)) {
                        proc_unlock(p);
                        KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_FRCEXIT) | DBG_FUNC_NONE,
                                              p->p_pid, W_EXITCODE(ENOTSUP, 0), 4, 0, 0);
                        exit1(p, W_EXITCODE(ENOTSUP, 0), retval);
-                       /* drop funnel before we return */
+
                        thread_exception_return();
                        /* NOTREACHED */
                }
@@ -156,20 +164,38 @@ ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
         *      Intercept and deal with "please trace me" request.
         */      
        if (uap->req == PT_TRACE_ME) {
-               proc_lock(p);
-               SET(p->p_lflag, P_LTRACED);
-               /* Non-attached case, our tracer is our parent. */
-               p->p_oppid = p->p_ppid;
-               /* Check whether child and parent are allowed to run modified
-                * code (they'll have to) */
-               struct proc *pproc=proc_find(p->p_oppid);
-               proc_unlock(p);
-               cs_allow_invalid(p);
-               if(pproc) {
+retry_trace_me:;
+               proc_t pproc = proc_parent(p);
+               if (pproc == NULL)
+                       return (EINVAL);
+#if CONFIG_MACF
+               /*
+                * NB: Cannot call kauth_authorize_process(..., KAUTH_PROCESS_CANTRACE, ...)
+                *     since that assumes the process being checked is the current process
+                *     when, in this case, it is the current process's parent.
+                *     Most of the other checks in cantrace() don't apply either.
+                */
+               if ((error = mac_proc_check_debug(pproc, p)) == 0) {
+#endif
+                       proc_lock(p);
+                       /* Make sure the process wasn't re-parented. */
+                       if (p->p_ppid != pproc->p_pid) {
+                               proc_unlock(p);
+                               proc_rele(pproc);
+                               goto retry_trace_me;
+                       }
+                       SET(p->p_lflag, P_LTRACED);
+                       /* Non-attached case, our tracer is our parent. */
+                       p->p_oppid = p->p_ppid;
+                       proc_unlock(p);
+                       /* Child and parent will have to be able to run modified code. */
+                       cs_allow_invalid(p);
                        cs_allow_invalid(pproc);
-                       proc_rele(pproc);
+#if CONFIG_MACF
                }
-               return(0);
+#endif
+               proc_rele(pproc);
+               return (error);
        }
        if (uap->req == PT_SIGEXC) {
                proc_lock(p);
@@ -200,12 +226,22 @@ ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
 
        task = t->task;
        if (uap->req == PT_ATTACHEXC) {
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
                uap->req = PT_ATTACH;
                tr_sigexc = 1;
        }
        if (uap->req == PT_ATTACH) {
+#pragma clang diagnostic pop
                int             err;
-               
+
+#if CONFIG_EMBEDDED
+               if (tr_sigexc == 0) {
+                       error = ENOTSUP;
+                       goto out;
+               }
+#endif
+
                if ( kauth_authorize_process(proc_ucred(p), KAUTH_PROCESS_CANTRACE, 
                                                                         t, (uintptr_t)&err, 0, 0) == 0 ) {
                        /* it's OK to attach */
@@ -347,8 +383,13 @@ ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
                }
 
                if (uap->data != 0) {
+#if CONFIG_MACF
+                       error = mac_proc_check_signal(p, t, uap->data);
+                       if (0 != error)
+                               goto out;
+#endif
                        psignal(t, uap->data);
-                }
+               }
 
                if (uap->req == PT_STEP) {
                        /*
@@ -403,8 +444,10 @@ ptrace(struct proc *p, struct ptrace_args *uap, int32_t *retval)
                        goto out;
                }
                th_act = port_name_to_thread(CAST_MACH_PORT_TO_NAME(uap->addr));
-               if (th_act == THREAD_NULL)
-                       return (ESRCH);
+               if (th_act == THREAD_NULL) {
+                       error = ESRCH;
+                       goto out;
+               }
                ut = (uthread_t)get_bsdthread_info(th_act);
                if (uap->data)
                        ut->uu_siglist |= sigmask(uap->data);
@@ -474,5 +517,13 @@ cantrace(proc_t cur_procp, kauth_cred_t creds, proc_t traced_procp, int *errp)
                *errp = EBUSY;
                return (0);
        }
+
+#if CONFIG_MACF
+       if ((my_err = mac_proc_check_debug(cur_procp, traced_procp)) != 0) {
+               *errp = my_err;
+               return (0);
+       }
+#endif
+
        return(1);
 }