diff mbox series

[081/110] xfs: tighten up validation of root block in inode forks

Message ID 171142132547.2215168.17356335150848921646.stgit@frogsfrogsfrogs (mailing list archive)
State Superseded, archived
Headers show
Series [001/110] xfs: convert kmem_zalloc() to kzalloc() | expand

Commit Message

Darrick J. Wong March 26, 2024, 3:49 a.m. UTC 
From: Christoph Hellwig <hch@lst.de>

Source kernel commit: d477f1749f00899c71605ea01aba0ce67e030471

Check that root blocks that sit in the inode fork and thus have a NULL
bp don't have siblings.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 libxfs/xfs_btree.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/libxfs/xfs_btree.c b/libxfs/xfs_btree.c
index 0b5002540b50..2f5848b9d51b 100644
--- a/libxfs/xfs_btree.c
+++ b/libxfs/xfs_btree.c
@@ -104,7 +104,7 @@  __xfs_btree_check_lblock(
 {
 	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_failaddr_t		fa;
-	xfs_fsblock_t		fsb = NULLFSBLOCK;
+	xfs_fsblock_t		fsb;
 
 	if (xfs_has_crc(mp)) {
 		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -124,9 +124,19 @@  __xfs_btree_check_lblock(
 	    cur->bc_ops->get_maxrecs(cur, level))
 		return __this_address;
 
-	if (bp)
-		fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+	/*
+	 * For inode-rooted btrees, the root block sits in the inode fork.  In
+	 * that case bp is NULL, and the block must not have any siblings.
+	 */
+	if (!bp) {
+		if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK))
+			return __this_address;
+		if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK))
+			return __this_address;
+		return NULL;
+	}
 
+	fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
 	fa = xfs_btree_check_lblock_siblings(mp, fsb, block->bb_u.l.bb_leftsib);
 	if (!fa)
 		fa = xfs_btree_check_lblock_siblings(mp, fsb,