cfq_get_queue: fix possible NULL pointer access

cfq_get_queue()->cfq_find_alloc_queue() can fail, check the returned value.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

Note that this isn't a bug at the moment, since the regular IO path
does not call this path without __GFP_WAIT set. However, it could be a
future bug, so I've applied it.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Oleg Nesterov 2007-10-23 15:08:21 +02:00 committed by Jens Axboe
parent abbeb88d00
commit 0a0836a09c

View File

@ -1443,8 +1443,11 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct task_struct *tsk,
cfqq = *async_cfqq;
}
if (!cfqq)
if (!cfqq) {
cfqq = cfq_find_alloc_queue(cfqd, is_sync, tsk, gfp_mask);
if (!cfqq)
return NULL;
}
/*
* pin the queue now that it's allocated, scheduler exit will prune it