[PATCH 5.10 36/40] fs: quota: fix array-index-out-of-bounds bug by passing correct argument to vfs_cleanup_quota_inode()

Greg Kroah-Hartman
2020-12-23T15:35:58Z

From: Anant Thazhemadam <anant.thazhemadam@gmail.com>

commit e51d68e76d604c6d5d1eb13ae1d6da7f6c8c0dfc upstream.

When dquot_resume() was last updated, the argument that got passed
to vfs_cleanup_quota_inode was incorrectly set.

If type = -1 and dquot_load_quota_sb() returns a negative value,
then vfs_cleanup_quota_inode() gets called with -1 passed as an
argument, and this leads to an array-index-out-of-bounds bug.

Fix this issue by correctly passing the arguments.

Fixes: ae45f07d47cc ("quota: Simplify dquot_resume()")
Link: https://lore.kernel.org/r/20201208194338.7064-1-anant.thazhemadam@gmail.com
Reported-by: syzbot+2643e825238d7aabb37f@syzkaller.appspotmail.com
Tested-by: syzbot+2643e825238d7aabb37f@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/quota/dquot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2455,7 +2455,7 @@ int dquot_resume(struct super_block *sb,
ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id,
flags);
if (ret < 0)
- vfs_cleanup_quota_inode(sb, type);
+ vfs_cleanup_quota_inode(sb, cnt);
}

return ret;