From: Anant Thazhemadam <anant.thazhemadam@gmail.com>
To: Jan Kara <jack@suse.com>
Cc: linux-kernel@vger.kernel.org,
Anant Thazhemadam <anant.thazhemadam@gmail.com>,
syzbot+2643e825238d7aabb37f@syzkaller.appspotmail.com
Subject: [PATCH] fs: quota: fix array-index-out-of-bounds bug by passing correct argument to vfs_cleanup_quota_inode()
Date: Wed, 9 Dec 2020 01:13:38 +0530 [thread overview]
Message-ID: <20201208194338.7064-1-anant.thazhemadam@gmail.com> (raw)
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()")
Reported-by: syzbot+2643e825238d7aabb37f@syzkaller.appspotmail.com
Tested-by: syzbot+2643e825238d7aabb37f@syzkaller.appspotmail.com
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
---
If type = -1 is passed as an argument to vfs_cleanup_quota_inode(),
it causes an array-index-out-of-bounds error since dqopt->files[-1]
can be potentially attempted to be accessed.
Before the bisected commit introduced this bug, vfs_load_quota_inode()
was being directly called in dquot_resume(), and subsequently
vfs_cleanup_quota_inode() was called with the cnt value as argument.
fs/quota/dquot.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index bb02989d92b6..4f1373463766 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2455,7 +2455,7 @@ int dquot_resume(struct super_block *sb, int type)
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;
--
2.25.1
next reply other threads:[~2020-12-08 20:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 19:43 Anant Thazhemadam [this message]
2020-12-09 9:07 ` [PATCH] fs: quota: fix array-index-out-of-bounds bug by passing correct argument to vfs_cleanup_quota_inode() Jan Kara
2020-12-09 17:53 ` Anant Thazhemadam
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