6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joseph Qi [ Upstream commit 775c17386a6fd695f999d4cda90e3931386570dd ] 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 Reviewed-by: Heming Zhao Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Signed-off-by: Andrew Morton Stable-dep-of: bc70726ddad5 ("ocfs2: validate directory-index entry counts when reading metadata") Signed-off-by: Sasha Levin --- fs/ocfs2/dir.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 49eb03107caa8..895d3d367b63c 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -580,7 +580,7 @@ static int ocfs2_validate_dx_root(struct super_block *sb, mlog(ML_ERROR, "Checksum failed for dir index root block %llu\n", (unsigned long long)bh->b_blocknr); - return ret; + goto bail; } if (!OCFS2_IS_VALID_DX_ROOT(dx_root)) { @@ -588,8 +588,32 @@ static int ocfs2_validate_dx_root(struct super_block *sb, "Dir Index Root # %llu has bad signature %.*s\n", (unsigned long long)le64_to_cpu(dx_root->dr_blkno), 7, dx_root->dr_signature); + goto bail; + } + + if (!(dx_root->dr_flags & OCFS2_DX_FLAG_INLINE)) { + struct ocfs2_extent_list *el = &dx_root->dr_list; + + if (le16_to_cpu(el->l_count) != ocfs2_extent_recs_per_dx_root(sb)) { + ret = ocfs2_error(sb, + "Dir Index Root # %llu has invalid l_count %u (expected %u)\n", + (unsigned long long)le64_to_cpu(dx_root->dr_blkno), + le16_to_cpu(el->l_count), + ocfs2_extent_recs_per_dx_root(sb)); + goto bail; + } + + if (le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count)) { + ret = ocfs2_error(sb, + "Dir Index Root # %llu has invalid l_next_free_rec %u (l_count %u)\n", + (unsigned long long)le64_to_cpu(dx_root->dr_blkno), + le16_to_cpu(el->l_next_free_rec), + le16_to_cpu(el->l_count)); + goto bail; + } } +bail: return ret; } -- 2.53.0