On 1/17/24 1:16 PM, Gabriel Ryan wrote: > We found a race in the block message queue for kernel v5.18-rc5 using > a race testing tool we are developing. We are reporting this race > because it appears to be potentially harmful. The race occurs in > > block/blk-mq-sched.c:333 blk_mq_sched_dispatch_requests > > hctx->run++; > > where multiple threads can schedule dispatch requests and increment > the request counter htctx->run simultaneously. This appears to lead to > undefined behavior where multiple conflicting updates to the hctx->run > value could result in it not matching the number of requests that > have been scheduled with calls to blk_mq_sched_dispatch_requests. I suggest you take a closer look at how that variable is actually used. -- Jens Axboe
