Commit 0a0836a0 authored Oct 23, 2007 by Oleg Nesterov Committed by Jens Axboe Oct 29, 2007

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>

parent abbeb88d

block/cfq-iosched.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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