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| author | Joseph Qi <joseph.qi@linux.alibaba.com> | 2026-09-05 22:21:44 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-10-06 19:03:04 -0700 |
| commit | 9e35bebc8b25fee008b4e7d4bb1a07dcfd4c1743 (patch) | |
| tree | e11702064d310e497405db5984907f1875fdd66c | |
| parent | 7b9f248353afc634b3b713b2ec662dac58f3820f (diff) | |
| download | linux-next-9e35bebc8b25fee008b4e7d4bb1a07dcfd4c1743.tar.gz linux-next-9e35bebc8b25fee008b4e7d4bb1a07dcfd4c1743.zip | |
ocfs2: validate dl_blkno and dl_fs_generation of dir index leaf blocks
ocfs2_validate_dx_leaf() checks the checksum, the signature and the entry
list counts, but it never checks dl_blkno or dl_fs_generation. The inode,
extent block, xattr block, refcount block and dir index root validators
all check the on-disk block number against bh->b_blocknr and the
generation against the superblock, and both dir index leaf fields are
documented as "Must match super block".
Without the checks, a stale dir index leaf block left on the device from a
previously formatted filesystem at the same physical block number can pass
validation as long as its signature, entry counts and checksum match. Its
index entries would then be used in the new filesystem context.
Both fields are written unconditionally when a leaf block is formatted in
ocfs2_dx_dir_format_cluster(), from the live superblock generation and the
real block number, so a correctly formatted filesystem cannot trip the new
checks. The leaf block number read back here comes from on-disk dir index
root extent records.
Reject dir index leaf blocks whose dl_blkno or dl_fs_generation does not
match, like the dir index root validator does.
Link: https://lore.kernel.org/20260905142144.2869105-2-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Heming Zhao <heming.zhao@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
| -rw-r--r-- | fs/ocfs2/dir.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 329680b46227..55c4a305a282 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -733,6 +733,18 @@ static int ocfs2_validate_dx_leaf(struct super_block *sb, return ocfs2_error(sb, "Dir Index Leaf has bad signature %.*s\n", 7, dx_leaf->dl_signature); + if (le64_to_cpu(dx_leaf->dl_blkno) != bh->b_blocknr) + return ocfs2_error(sb, + "Dir Index Leaf # %llu has an invalid dl_blkno of %llu\n", + (unsigned long long)bh->b_blocknr, + (unsigned long long)le64_to_cpu(dx_leaf->dl_blkno)); + + if (le32_to_cpu(dx_leaf->dl_fs_generation) != OCFS2_SB(sb)->fs_generation) + return ocfs2_error(sb, + "Dir Index Leaf # %llu has an invalid dl_fs_generation of #%u\n", + (unsigned long long)bh->b_blocknr, + le32_to_cpu(dx_leaf->dl_fs_generation)); + if (le16_to_cpu(dx_leaf->dl_list.de_count) != ocfs2_dx_entries_per_leaf(sb)) return ocfs2_error(sb, |