From 4408ea41c0ab4b711d4da44dd954fb06dce6c3f8 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Tue, 19 Oct 2010 00:24:21 +0200
Subject: [PATCH] quota: Fix possible oops in __dquot_initialize()
When quotaon(8) races with __dquot_initialize() or dqget() fails because
of EIO, ENOSPC, or similar error, we could possibly dereference NULL pointer
in inode->i_dquot[cnt]. Add proper checking.
Reported-by: Dmitry Monakhov <dmonakhov@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/quota/dquot.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 1bc38f56fa7c..0fed41e6efcd 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1386,6 +1386,9 @@ static void __dquot_initialize(struct inode *inode, int type)
/* Avoid races with quotaoff() */
if (!sb_has_quota_active(sb, cnt))
continue;
+ /* We could race with quotaon or dqget() could have failed */
+ if (!got[cnt])
+ continue;
if (!inode->i_dquot[cnt]) {
inode->i_dquot[cnt] = got[cnt];
got[cnt] = NULL;
--
2.34.1