Commit 4d0e1f21 authored by Fengnan Chang's avatar Fengnan Chang Committed by Jens Axboe
Browse files

blk-mq: use queue_hctx in blk_mq_map_queue_type 



Some caller of blk_mq_map_queue_type now didn't grab
'q_usage_counter', such as blk_mq_cpu_mapped_to_hctx, so we need
protect 'queue_hw_ctx' through rcu.

Also checked all other functions, no more missed cases.

Fixes: 89e1fb7c ("blk-mq: fix potential uaf for 'queue_hw_ctx'")
Reported-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarFengnan Chang <changfengnan@bytedance.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c1536df9

block/blk-mq.h

+1 −1
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue * 
							  enum hctx_type type,

							  unsigned int cpu)

{

	return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];

	return queue_hctx((q), (q->tag_set->map[type].mq_map[cpu]));

}



static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)