From e11e5116171dedeaf63735931e72ad5de0f30ed5 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Wed, 10 Feb 2021 14:04:00 -0800 Subject: [PATCH] nvme-tcp: fix crash triggered with a dataless request submission write-zeros has a bio, but does not have any data buffers associated with it. Hence should not initialize the request iter for it (which attempts to reference the bi_io_vec (and crash). -- run blktests nvme/012 at 2021-02-05 21:53:34 BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 15 PID: 12069 Comm: kworker/15:2H Tainted: G S I 5.11.0-rc6+ #1 Hardware name: Dell Inc. PowerEdge R640/06NR82, BIOS 2.10.0 11/12/2020 Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:nvme_tcp_init_iter+0x7d/0xd0 [nvme_tcp] RSP: 0018:ffffbd084447bd18 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffa0bba9f3ce80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000002000000 RBP: ffffa0ba8ac6fec0 R08: 0000000002000000 R09: 0000000000000000 R10: 0000000002800809 R11: 0000000000000000 R12: 0000000000000000 R13: ffffa0bba9f3cf90 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa0c9ff9c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000001c9c6c005 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: nvme_tcp_queue_rq+0xef/0x330 [nvme_tcp] blk_mq_dispatch_rq_list+0x11c/0x7c0 ? blk_mq_flush_busy_ctxs+0xf6/0x110 __blk_mq_sched_dispatch_requests+0x12b/0x170 blk_mq_sched_dispatch_requests+0x30/0x60 __blk_mq_run_hw_queue+0x2b/0x60 process_one_work+0x1cb/0x360 ? process_one_work+0x360/0x360 worker_thread+0x30/0x370 ? process_one_work+0x360/0x360 kthread+0x116/0x130 ? kthread_park+0x80/0x80 ret_from_fork+0x1f/0x30 -- Fixes: cb9b870fba3e ("nvme-tcp: fix wrong setting of request iov_iter") Reported-by: Yi Zhang Signed-off-by: Sagi Grimberg Reviewed-by: Keith Busch Reviewed-by: Chaitanya Kulkarni Tested-by: Yi Zhang Signed-off-by: Christoph Hellwig --- drivers/nvme/host/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 619b0d8..69f59d2 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -2271,7 +2271,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns, req->data_len = blk_rq_nr_phys_segments(rq) ? blk_rq_payload_bytes(rq) : 0; req->curr_bio = rq->bio; - if (req->curr_bio) + if (req->curr_bio && req->data_len) nvme_tcp_init_iter(req, rq_data_dir(rq)); if (rq_data_dir(rq) == WRITE && -- 2.7.4