From: "Darrick J. Wong" darrick.wong@oracle.com
stable inclusion from linux-4.19.158 commit b7fec5a9a726e9e2a095d53b6de4e62bf179b481
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[ Upstream commit 6ff646b2ceb0eec916101877f38da0b73e3a5b7f ]
Keys for extent interval records in the reverse mapping btree are supposed to be computed as follows:
(physical block, owner, fork, is_btree, is_unwritten, offset)
This provides users the ability to look up a reverse mapping from a bmbt record -- start with the physical block; then if there are multiple records for the same block, move on to the owner; then the inode fork type; and so on to the file offset.
However, the key comparison functions incorrectly remove the fork/btree/unwritten information that's encoded in the on-disk offset. This means that lookup comparisons are only done with:
(physical block, owner, offset)
This means that queries can return incorrect results. On consistent filesystems this hasn't been an issue because blocks are never shared between forks or with bmbt blocks; and are never unwritten. However, this bug means that online repair cannot always detect corruption in the key information in internal rmapbt nodes.
Found by fuzzing keys[1].attrfork = ones on xfs/371.
Fixes: 4b8ed67794fe ("xfs: add rmap btree operations") Signed-off-by: Darrick J. Wong darrick.wong@oracle.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/xfs/libxfs/xfs_rmap_btree.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c index f79cf040d745..77528f413286 100644 --- a/fs/xfs/libxfs/xfs_rmap_btree.c +++ b/fs/xfs/libxfs/xfs_rmap_btree.c @@ -247,8 +247,8 @@ xfs_rmapbt_key_diff( else if (y > x) return -1;
- x = XFS_RMAP_OFF(be64_to_cpu(kp->rm_offset)); - y = rec->rm_offset; + x = be64_to_cpu(kp->rm_offset); + y = xfs_rmap_irec_offset_pack(rec); if (x > y) return 1; else if (y > x) @@ -279,8 +279,8 @@ xfs_rmapbt_diff_two_keys( else if (y > x) return -1;
- x = XFS_RMAP_OFF(be64_to_cpu(kp1->rm_offset)); - y = XFS_RMAP_OFF(be64_to_cpu(kp2->rm_offset)); + x = be64_to_cpu(kp1->rm_offset); + y = be64_to_cpu(kp2->rm_offset); if (x > y) return 1; else if (y > x) @@ -393,8 +393,8 @@ xfs_rmapbt_keys_inorder( return 1; else if (a > b) return 0; - a = XFS_RMAP_OFF(be64_to_cpu(k1->rmap.rm_offset)); - b = XFS_RMAP_OFF(be64_to_cpu(k2->rmap.rm_offset)); + a = be64_to_cpu(k1->rmap.rm_offset); + b = be64_to_cpu(k2->rmap.rm_offset); if (a <= b) return 1; return 0; @@ -423,8 +423,8 @@ xfs_rmapbt_recs_inorder( return 1; else if (a > b) return 0; - a = XFS_RMAP_OFF(be64_to_cpu(r1->rmap.rm_offset)); - b = XFS_RMAP_OFF(be64_to_cpu(r2->rmap.rm_offset)); + a = be64_to_cpu(r1->rmap.rm_offset); + b = be64_to_cpu(r2->rmap.rm_offset); if (a <= b) return 1; return 0;