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authorBart Van Assche <bart.vanassche@wdc.com>2017-10-11 10:27:26 -0700
committerDoug Ledford <dledford@redhat.com>2017-10-18 10:49:54 -0400
commit8a0d18c62121d3c554a83eb96e2752861d84d937 (patch)
treec4d4b4e6e0f29a06e81108bb8bad9300082c55ee /drivers/infiniband/ulp/srp
parentIB/srpt: Change default behavior from using SRQ to using RC (diff)
downloadlinux-dev-8a0d18c62121d3c554a83eb96e2752861d84d937.tar.xz
linux-dev-8a0d18c62121d3c554a83eb96e2752861d84d937.zip
IB/srp: Avoid that a cable pull can trigger a kernel crash
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 <bart.vanassche@wdc.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Cc: <stable@vger.kernel.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/ulp/srp')
-rw-r--r--drivers/infiniband/ulp/srp/ib_srp.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 778a08250f16..8ceb4bb011f1 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -665,12 +665,19 @@ static void srp_path_rec_completion(int status,
static int srp_lookup_path(struct srp_rdma_ch *ch)
{
struct srp_target_port *target = ch->target;
- int ret;
+ int ret = -ENODEV;
ch->path.numb_path = 1;
init_completion(&ch->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;
+
ch->path_query_id = ib_sa_path_rec_get(&srp_sa_client,
target->srp_host->srp_dev->dev,
target->srp_host->port,
@@ -684,18 +691,24 @@ static int srp_lookup_path(struct srp_rdma_ch *ch)
GFP_KERNEL,
srp_path_rec_completion,
ch, &ch->path_query);
- if (ch->path_query_id < 0)
- return ch->path_query_id;
+ ret = ch->path_query_id;
+ if (ret < 0)
+ goto put;
ret = wait_for_completion_interruptible(&ch->done);
if (ret < 0)
- return ret;
+ goto put;
- if (ch->status < 0)
+ ret = ch->status;
+ if (ret < 0)
shost_printk(KERN_WARNING, target->scsi_host,
PFX "Path record query failed\n");
- return ch->status;
+put:
+ scsi_host_put(target->scsi_host);
+
+out:
+ return ret;
}
static int srp_send_req(struct srp_rdma_ch *ch, bool multich)