From 2d87d455ead2cbdee7e60463cddc5bff3f98c912 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 27 Oct 2022 16:57:09 +0800 Subject: blk-mq: don't add non-pt request with ->end_io to batch dm-rq implements ->end_io callback for request issued to underlying queue, and it isn't passthrough request. Commit ab3e1d3bbab9 ("block: allow end_io based requests in the completion batch handling") doesn't clear rq->bio and rq->__data_len for request with ->end_io in blk_mq_end_request_batch(), and this way is actually dangerous, but so far it is only for nvme passthrough request. dm-rq needs to clean up remained bios in case of partial completion, and req->bio is required, then use-after-free is triggered, so the underlying clone request can't be completed in blk_mq_end_request_batch. Fix panic by not adding such request into batch list, and the issue can be triggered simply by exposing nvme pci to dm-mpath simply. Fixes: ab3e1d3bbab9 ("block: allow end_io based requests in the completion batch handling") Cc: dm-devel@redhat.com Cc: Mike Snitzer Reported-by: Changhui Zhong Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20221027085709.513175-1-ming.lei@redhat.com Signed-off-by: Jens Axboe --- include/linux/blk-mq.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index ba18e9bdb799..d6119c5d1069 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -853,7 +853,8 @@ static inline bool blk_mq_add_to_batch(struct request *req, struct io_comp_batch *iob, int ioerror, void (*complete)(struct io_comp_batch *)) { - if (!iob || (req->rq_flags & RQF_ELV) || ioerror) + if (!iob || (req->rq_flags & RQF_ELV) || ioerror || + (req->end_io && !blk_rq_is_passthrough(req))) return false; if (!iob->complete) -- cgit v1.2.3