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>
This commit is contained in:
Jan Kara 2010-10-19 00:24:21 +02:00
parent a4c18ad2ee
commit 4408ea41c0

View File

@ -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;