From bbfc3c5d6c7882dc65c1230e781644e35c29839f Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Tue, 31 Jan 2017 22:36:50 -0800 Subject: [PATCH] block: queue lock must be acquired when iterating over rls 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 Signed-off-by: Jens Axboe --- block/blk-core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/blk-core.c b/block/blk-core.c index 02833ce..b2df55a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -527,12 +527,14 @@ 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); -- 2.7.4