From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Tahsin Erdogan To: Jens Axboe , linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Tahsin Erdogan Subject: [PATCH] block: queue lock must be acquired when iterating over rls Date: Tue, 31 Jan 2017 22:36:50 -0800 Message-Id: <20170201063650.15060-1-tahsin@google.com> List-ID: blk_set_queue_dying() does not acquire queue lock before it calls blk_queue_for_each_rl(). This allows a racing blkg_destroy() to remove blkg->q_node from the linked list and have blk_queue_for_each_rl() loop infitely over the removed blkg->q_node list node. Signed-off-by: Tahsin Erdogan --- block/blk-core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-core.c b/block/blk-core.c index 61ba08c58b64..0488a2b55bf0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -525,12 +525,14 @@ void blk_set_queue_dying(struct request_queue *q) else { struct request_list *rl; + spin_lock_irq(q->queue_lock); blk_queue_for_each_rl(rl, q) { if (rl->rq_pool) { wake_up(&rl->wait[BLK_RW_SYNC]); wake_up(&rl->wait[BLK_RW_ASYNC]); } } + spin_unlock_irq(q->queue_lock); } } EXPORT_SYMBOL_GPL(blk_set_queue_dying); -- 2.11.0.483.g087da7b7c-goog