From 6a02a61e81c231cc5c680c5dbf8665275147ac52 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 12 Aug 2022 14:03:17 -0700 Subject: [PATCH] nvmet: fix a use-after-free Fix the following use-after-free complaint triggered by blktests nvme/004: BUG: KASAN: user-memory-access in blk_mq_complete_request_remote+0xac/0x350 Read of size 4 at addr 0000607bd1835943 by task kworker/13:1/460 Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop] Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e print_report.cold+0x36/0x1e2 kasan_report+0xb9/0xf0 __asan_load4+0x6b/0x80 blk_mq_complete_request_remote+0xac/0x350 nvme_loop_queue_response+0x1df/0x275 [nvme_loop] __nvmet_req_complete+0x132/0x4f0 [nvmet] nvmet_req_complete+0x15/0x40 [nvmet] nvmet_execute_io_connect+0x18a/0x1f0 [nvmet] nvme_loop_execute_work+0x20/0x30 [nvme_loop] process_one_work+0x56e/0xa70 worker_thread+0x2d1/0x640 kthread+0x183/0x1c0 ret_from_fork+0x1f/0x30 Cc: stable@vger.kernel.org Fixes: a07b4970f464 ("nvmet: add a generic NVMe target") Signed-off-by: Bart Van Assche Signed-off-by: Christoph Hellwig --- drivers/nvme/target/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index a134579..7f4083c 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -735,6 +735,8 @@ static void nvmet_set_error(struct nvmet_req *req, u16 status) static void __nvmet_req_complete(struct nvmet_req *req, u16 status) { + struct nvmet_ns *ns = req->ns; + if (!req->sq->sqhd_disabled) nvmet_update_sq_head(req); req->cqe->sq_id = cpu_to_le16(req->sq->qid); @@ -745,9 +747,9 @@ static void __nvmet_req_complete(struct nvmet_req *req, u16 status) trace_nvmet_req_complete(req); - if (req->ns) - nvmet_put_namespace(req->ns); req->ops->queue_response(req); + if (ns) + nvmet_put_namespace(ns); } void nvmet_req_complete(struct nvmet_req *req, u16 status) -- 2.7.4