xnu-4903.221.2.tar.gz

[apple/xnu.git] / bsd / vfs / vfs_attrlist.c

diff --git a/bsd/vfs/vfs_attrlist.c b/bsd/vfs/vfs_attrlist.c
index f5710e862113d8cfaedbbde0f644952f869aeb1d..cd8cbacad02a77712121ceb8ffc4688285fa2497 100644 (file)
--- a/bsd/vfs/vfs_attrlist.c
+++ b/bsd/vfs/vfs_attrlist.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1995-2017 Apple Inc. All rights reserved.
+ * Copyright (c) 1995-2018 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
@@ -1136,12 +1136,33 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
         * Note that since we won't ever copy out more than the caller requested,
         * we never need to allocate more than they offer.
         */
-       ab.allocated = ulmin(bufferSize, fixedsize + varsize);
-       if (ab.allocated > ATTR_MAX_BUFFER) {
+       ab.allocated = fixedsize + varsize;
+       if (((size_t)ab.allocated) > ATTR_MAX_BUFFER) {
                error = ENOMEM;
                VFS_DEBUG(ctx, vp, "ATTRLIST - ERROR: buffer size too large (%d limit %d)", ab.allocated, ATTR_MAX_BUFFER);
                goto out;
        }
+
+       if (return_valid &&
+           (ab.allocated < (ssize_t)(sizeof(uint32_t) + sizeof(attribute_set_t))) &&
+           !(options & FSOPT_REPORT_FULLSIZE)) {
+               uint32_t num_bytes_valid = sizeof(uint32_t);
+               /*
+                * Not enough to return anything and we don't have to report
+                * how much space is needed. Get out now.
+                * N.B. - We have only been called after having verified that
+                * attributeBuffer is at least sizeof(uint32_t);
+                */
+               if (UIO_SEG_IS_USER_SPACE(segflg)) {
+                       error = copyout(&num_bytes_valid,
+                           CAST_USER_ADDR_T(attributeBuffer), num_bytes_valid);
+               } else {
+                       bcopy(&num_bytes_valid, (void *)attributeBuffer,
+                           (size_t)num_bytes_valid);
+               }
+               goto out;
+       }
+
        MALLOC(ab.base, char *, ab.allocated, M_TEMP, M_ZERO | M_WAITOK);
        if (ab.base == NULL) {
                error = ENOMEM;
@@ -1161,6 +1182,10 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
        ab.needed = fixedsize + varsize;
 
        /* common attributes **************************************************/
+       if (alp->commonattr & ATTR_CMN_ERROR) {
+               ATTR_PACK4(ab, 0);
+               ab.actual.commonattr |= ATTR_CMN_ERROR;
+       }
        if (alp->commonattr & ATTR_CMN_NAME) {
                attrlist_pack_string(&ab, cnp, cnl);
                ab.actual.commonattr |= ATTR_CMN_NAME;
@@ -1456,10 +1481,11 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
         * of the result buffer, even if we copied less out.  The caller knows how big a buffer
         * they gave us, so they can always check for truncation themselves.
         */
-       *(uint32_t *)ab.base = (options & FSOPT_REPORT_FULLSIZE) ? ab.needed : imin(ab.allocated, ab.needed);
-       
+       *(uint32_t *)ab.base = (options & FSOPT_REPORT_FULLSIZE) ? ab.needed : imin(bufferSize, ab.needed);
+
        /* Return attribute set output if requested. */
-       if (return_valid) {
+       if (return_valid &&
+           (ab.allocated >= (ssize_t)(sizeof(uint32_t) + sizeof(ab.actual)))) {
                ab.actual.commonattr |= ATTR_CMN_RETURNED_ATTRS;
                if (pack_invalid) {
                        /* Only report the attributes that are valid */
@@ -1471,9 +1497,9 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
 
        if (UIO_SEG_IS_USER_SPACE(segflg))
                error = copyout(ab.base, CAST_USER_ADDR_T(attributeBuffer),
-                               ab.allocated);
+                               ulmin(bufferSize, ab.needed));
        else
-               bcopy(ab.base, (void *)attributeBuffer, (size_t)ab.allocated);
+               bcopy(ab.base, (void *)attributeBuffer, (size_t)ulmin(bufferSize, ab.needed));
 
 out:
        if (vs.f_vol_name != NULL)
@@ -2775,6 +2801,9 @@ getattrlist_internal(vfs_context_t ctx, vnode_t vp, struct attrlist  *alp,
        // must be true for fork attributes to be used as new common attributes
        const int use_fork = (options & FSOPT_ATTR_CMN_EXTENDED) != 0;
 
+       if (bufferSize < sizeof(uint32_t))
+               return (ERANGE);
+
        proc_is64 = proc_is64bit(vfs_context_proc(ctx));
 
        if (segflg == UIO_USERSPACE) {
@@ -3675,6 +3704,7 @@ getattrlistbulk(proc_t p, struct getattrlistbulk_args *uap, int32_t *retval)
        struct fileproc *fp;
        struct fd_vn_data *fvdata;
        vfs_context_t ctx;
+       uthread_t ut;
        enum uio_seg segflg;
        int count;
        uio_t auio = NULL;
@@ -3694,6 +3724,7 @@ getattrlistbulk(proc_t p, struct getattrlistbulk_args *uap, int32_t *retval)
        fvdata = NULL;
        eofflag = 0;
        ctx = vfs_context_current();
+       ut = get_bsdthread_info(current_thread());
        segflg = IS_64BIT_PROCESS(p) ? UIO_USERSPACE64 : UIO_USERSPACE32;
 
        if ((fp->f_fglob->fg_flag & FREAD) == 0) {
@@ -3840,8 +3871,14 @@ getattrlistbulk(proc_t p, struct getattrlistbulk_args *uap, int32_t *retval)
                        (void)getattrlist_setupvattr_all(&al, &va, VNON, NULL,
                            IS_64BIT_PROCESS(p), (uap->options & FSOPT_ATTR_CMN_EXTENDED));
 
+                       /*
+                        * Set UT_KERN_RAGE_VNODES to cause all vnodes created by the
+                        * filesystem to be rapidly aged.
+                        */
+                       ut->uu_flag |= UT_KERN_RAGE_VNODES;
                        error = VNOP_GETATTRLISTBULK(dvp, &al, &va, auio, NULL,
                            options, &eofflag, &count, ctx);
+                       ut->uu_flag &= ~UT_KERN_RAGE_VNODES;
 
                        FREE(va_name, M_TEMP);
 
@@ -3862,8 +3899,10 @@ getattrlistbulk(proc_t p, struct getattrlistbulk_args *uap, int32_t *retval)
                eofflag = 0;
                count = 0;
 
+               ut->uu_flag |= UT_KERN_RAGE_VNODES;
                error = readdirattr(dvp, fvdata, auio, &al, options,
                    &count, &eofflag, ctx);
+               ut->uu_flag &= ~UT_KERN_RAGE_VNODES;
        }
 
        if (count) {