xfs: validate attr remote value buffer owners

Check the owner field of xattr remote value blocks.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_attr_remote.c

@@ -280,12 +280,12 @@ xfs_attr_rmtval_copyout(
 	struct xfs_mount	*mp,
 	struct xfs_buf		*bp,
 	struct xfs_inode	*dp,
+	xfs_ino_t		owner,
 	int			*offset,
 	int			*valuelen,
 	uint8_t			**dst)
 {
 	char			*src = bp->b_addr;
-	xfs_ino_t		ino = dp->i_ino;
 	xfs_daddr_t		bno = xfs_buf_daddr(bp);
 	int			len = BBTOB(bp->b_length);
 	int			blksize = mp->m_attr_geo->blksize;
@@ -299,11 +299,11 @@ xfs_attr_rmtval_copyout(
 		byte_cnt = min(*valuelen, byte_cnt);
 
 		if (xfs_has_crc(mp)) {
-			if (xfs_attr3_rmt_hdr_ok(src, ino, *offset,
+			if (xfs_attr3_rmt_hdr_ok(src, owner, *offset,
 						  byte_cnt, bno)) {
 				xfs_alert(mp,
 "remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
-					bno, *offset, byte_cnt, ino);
+					bno, *offset, byte_cnt, owner);
 				xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
 				return -EFSCORRUPTED;
 			}
@@ -427,8 +427,7 @@ xfs_attr_rmtval_get(
 				return error;
 
 			error = xfs_attr_rmtval_copyout(mp, bp, args->dp,
-							&offset, &valuelen,
-							&dst);
+					args->owner, &offset, &valuelen, &dst);
 			xfs_buf_relse(bp);
 			if (error)
 				return error;