ocfs2: validate dx_root extent list fields during block read

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Patch series "ocfs2: consolidate extent list validation into block read
callbacks".

ocfs2 validates extent list fields (l_count, l_next_free_rec) at various
points during extent tree traversal.  This is fragile because each caller
must remember to check for corrupted on-disk data before using it.

This series moves those checks into the block read validation callbacks
(ocfs2_validate_dx_root and ocfs2_validate_extent_block), so corrupted
fields are caught early at block read time.  Redundant post-read checks
are then removed.


This patch (of 4):

Move the extent list l_count validation from ocfs2_dx_dir_lookup_rec()
into ocfs2_validate_dx_root(), so that corrupted on-disk fields are caught
early at block read time rather than during directory lookups.

Additionally, add a l_next_free_rec <= l_count check to prevent
out-of-bounds access when iterating over extent records.

Both checks are skipped for inline dx roots (OCFS2_DX_FLAG_INLINE), which
use dr_entries instead of dr_list.

Link: https://lkml.kernel.org/r/20260403090803.3860971-1-joseph.qi@linux.alibaba.com
Link: https://lkml.kernel.org/r/20260403090803.3860971-2-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

...

This commit is contained in:

Joseph Qi 2026-04-03 17:08:00 +08:00 • committed by Andrew Morton

parent 7de554cabf

commit 775c17386a

1 changed files with 25 additions and 9 deletions

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fs/ocfs2/dir.c

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