Commit 1b34743c authored by Dmitry Antipov's avatar Dmitry Antipov Committed by Andrew Morton
Browse files

ocfs2: add extra consistency check to ocfs2_dx_dir_lookup_rec() 

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: default avatar <syzbot+30b53487d00b4f7f0922@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=30b53487d00b4f7f0922


Signed-off-by: default avatarDmitry Antipov <dmantipov@yandex.ru>
Reviewed-by: default avatarJoseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: default avatarHeming Zhao <heming.zhao@suse.com&gt;>
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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2f26f58d

fs/ocfs2/dir.c

+8 −0
Original line number Diff line number Diff line
@@ -778,6 +778,14 @@ static int ocfs2_dx_dir_lookup_rec(struct inode *inode, 
	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);