1 files changed, 26 insertions, 5 deletions

diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c
index ea0b9628df18..a16b05c43e2e 100644
--- a/fs/xfs/libxfs/xfs_dir2_data.c
+++ b/fs/xfs/libxfs/xfs_dir2_data.c
@@ -178,6 +178,14 @@ __xfs_dir3_data_check(
 	while (offset < end) {
 		struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;
 		struct xfs_dir2_data_entry	*dep = bp->b_addr + offset;
+		unsigned int	reclen;
+
+		/*
+		 * Are the remaining bytes large enough to hold an
+		 * unused entry?
+		 */
+		if (offset > end - xfs_dir2_data_unusedsize(1))
+			return __this_address;
 
 		/*
 		 * If it's unused, look for the space in the bestfree table.
@@ -187,9 +195,13 @@ __xfs_dir3_data_check(
 		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 			xfs_failaddr_t	fa;
 
+			reclen = xfs_dir2_data_unusedsize(
+					be16_to_cpu(dup->length));
 			if (lastfree != 0)
 				return __this_address;
-			if (offset + be16_to_cpu(dup->length) > end)
+			if (be16_to_cpu(dup->length) != reclen)
+				return __this_address;
+			if (offset + reclen > end)
 				return __this_address;
 			if (be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) !=
 			    offset)
@@ -207,10 +219,18 @@ __xfs_dir3_data_check(
 				    be16_to_cpu(bf[2].length))
 					return __this_address;
 			}
-			offset += be16_to_cpu(dup->length);
+			offset += reclen;
 			lastfree = 1;
 			continue;
 		}
+
+		/*
+		 * This is not an unused entry. Are the remaining bytes
+		 * large enough for a dirent with a single-byte name?
+		 */
+		if (offset > end - xfs_dir2_data_entsize(mp, 1))
+			return __this_address;
+
 		/*
 		 * It's a real entry.  Validate the fields.
 		 * If this is a block directory then make sure it's
@@ -219,9 +239,10 @@ __xfs_dir3_data_check(
 		 */
 		if (dep->namelen == 0)
 			return __this_address;
-		if (!xfs_verify_dir_ino(mp, be64_to_cpu(dep->inumber)))
+		reclen = xfs_dir2_data_entsize(mp, dep->namelen);
+		if (offset + reclen > end)
 			return __this_address;
-		if (offset + xfs_dir2_data_entsize(mp, dep->namelen) > end)
+		if (!xfs_verify_dir_ino(mp, be64_to_cpu(dep->inumber)))
 			return __this_address;
 		if (be16_to_cpu(*xfs_dir2_data_entry_tag_p(mp, dep)) != offset)
 			return __this_address;
@@ -245,7 +266,7 @@ __xfs_dir3_data_check(
 			if (i >= be32_to_cpu(btp->count))
 				return __this_address;
 		}
-		offset += xfs_dir2_data_entsize(mp, dep->namelen);
+		offset += reclen;
 	}
 	/*
 	 * Need to have seen all the entries and all the bestfree slots.