From: Joseph Qi <joseph.qi@linux.alibaba.com> mainline inclusion from mainline-v7.3-rc1 commit 775c17386a6fd695f999d4cda90e3931386570dd category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/18855 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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.c... Link: https://lkml.kernel.org/r/20260403090803.3860971-2-joseph.qi@linux.alibaba.c... 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> Conflicts: fs/ocfs2/dir.c [The conflicts were due to not merge some related code.] Signed-off-by: Pu Lehui <pulehui@huawei.com> --- 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 4cc29b808d18..9fabb774e27f 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -582,7 +582,7 @@ 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)) { @@ -590,8 +590,32 @@ 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; } -- 2.34.1