xnu-4570.61.1.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..cde828a7b391bcfbd544975568144f8f1a2174b6 100644 (file)
--- a/bsd/vfs/vfs_attrlist.c
+++ b/bsd/vfs/vfs_attrlist.c
@@ -1142,6 +1142,27 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
                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;
@@ -1457,9 +1478,10 @@ getvolattrlist(vfs_context_t ctx, vnode_t vp, struct attrlist *alp,
         * 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);
-       
+
        /* 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 */
@@ -2775,6 +2797,9 @@ 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) {