From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41340 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752531AbeBKEdk (ORCPT ); Sat, 10 Feb 2018 23:33:40 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Bart Van Assche" , "Sagi Grimberg" , "Doug Ledford" Date: Sun, 11 Feb 2018 04:20:06 +0000 Message-ID: Subject: [PATCH 3.2 10/79] IB/srp: Avoid that a cable pull can trigger a kernel crash In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.2.99-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 8a0d18c62121d3c554a83eb96e2752861d84d937 upstream. This patch fixes the following kernel crash: general protection fault: 0000 [#1] PREEMPT SMP Workqueue: ib_mad2 timeout_sends [ib_core] Call Trace: ib_sa_path_rec_callback+0x1c4/0x1d0 [ib_core] send_handler+0xb2/0xd0 [ib_core] timeout_sends+0x14d/0x220 [ib_core] process_one_work+0x200/0x630 worker_thread+0x4e/0x3b0 kthread+0x113/0x150 Fixes: commit aef9ec39c47f ("IB: Add SCSI RDMA Protocol (SRP) initiator") Signed-off-by: Bart Van Assche Reviewed-by: Sagi Grimberg Signed-off-by: Doug Ledford [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -310,10 +310,19 @@ static void srp_path_rec_completion(int static int srp_lookup_path(struct srp_target_port *target) { + int ret = -ENODEV; + target->path.numb_path = 1; init_completion(&target->done); + /* + * Avoid that the SCSI host can be removed by srp_remove_target() + * before srp_path_rec_completion() is called. + */ + if (!scsi_host_get(target->scsi_host)) + goto out; + target->path_query_id = ib_sa_path_rec_get(&srp_sa_client, target->srp_host->srp_dev->dev, target->srp_host->port, @@ -327,16 +336,22 @@ static int srp_lookup_path(struct srp_ta GFP_KERNEL, srp_path_rec_completion, target, &target->path_query); - if (target->path_query_id < 0) - return target->path_query_id; + ret = target->path_query_id; + if (ret < 0) + goto put; wait_for_completion(&target->done); - if (target->status < 0) + ret = target->status; + if (ret < 0) shost_printk(KERN_WARNING, target->scsi_host, PFX "Path record query failed\n"); - return target->status; +put: + scsi_host_put(target->scsi_host); + +out: + return ret; } static int srp_send_req(struct srp_target_port *target)