+ ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec.patch added to mm-nonmm-unstable branch

+ ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: ocfs2: add extra consistency check to ocfs2_dx_dir_lookup_rec()
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Dmitry Antipov <dmantipov@yandex.ru>
Subject: ocfs2: add extra consistency check to ocfs2_dx_dir_lookup_rec()
Date: Tue, 7 Oct 2025 12:46:26 +0300

In 'ocfs2_dx_dir_lookup_rec()', check whether an extent list length of the
directory indexing block matches the one configured via the superblock
parameters established at mount, thus preventing an out-of-bounds accesses
while iterating over the extent records below.

Link: https://lkml.kernel.org/r/20251007094626.196143-1-dmantipov@yandex.ru
Reported-by: syzbot+30b53487d00b4f7f0922@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=30b53487d00b4f7f0922
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reviewed-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>
---

 fs/ocfs2/dir.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/fs/ocfs2/dir.c~ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec
+++ a/fs/ocfs2/dir.c
@@ -778,6 +778,14 @@ static int ocfs2_dx_dir_lookup_rec(struc
 	struct ocfs2_extent_block *eb;
 	struct ocfs2_extent_rec *rec = NULL;
 
+	if (le16_to_cpu(el->l_count) !=
+	    ocfs2_extent_recs_per_dx_root(inode->i_sb)) {
+		ret = ocfs2_error(inode->i_sb,
+				  "Inode %lu has invalid extent list length %u\n",
+				  inode->i_ino, le16_to_cpu(el->l_count));
+		goto out;
+	}
+
 	if (el->l_tree_depth) {
 		ret = ocfs2_find_leaf(INODE_CACHE(inode), el, major_hash,
 				      &eb_bh);
_

Patches currently in -mm which might be from dmantipov@yandex.ru are

ocfs2-add-extra-flags-check-in-ocfs2_ioctl_move_extents.patch
ocfs2-relax-bug-to-ocfs2_error-in-__ocfs2_move_extent.patch
ocfs2-annotate-flexible-array-members-with-__counted_by_le.patch
ocfs2-add-extra-consistency-check-to-ocfs2_dx_dir_lookup_rec.patch