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authorBart Van Assche <bart.vanassche@sandisk.com>2017-02-14 10:56:30 -0800
committerDoug Ledford <dledford@redhat.com>2017-02-19 09:51:52 -0500
commit6cb72bc1b40bb2c1750ee7a5ebade93bed49a5fb (patch)
tree36444ca18a6ca4c8e42b2dc4dec49f6a4befea28 /drivers/infiniband
parentd6c58dc40fec35ff6cdb350b53bce0fcf9143709 (diff)
IB/srp: Avoid that duplicate responses trigger a kernel bug
After srp_process_rsp() returns there is a short time during which the scsi_host_find_tag() call will return a pointer to the SCSI command that is being completed. If during that time a duplicate response is received, avoid that the following call stack appears: BUG: unable to handle kernel NULL pointer dereference at (null) IP: srp_recv_done+0x450/0x6b0 [ib_srp] Oops: 0000 [#1] SMP CPU: 10 PID: 0 Comm: swapper/10 Not tainted 4.10.0-rc7-dbg+ #1 Call Trace: <IRQ> __ib_process_cq+0x4b/0xd0 [ib_core] ib_poll_handler+0x1d/0x70 [ib_core] irq_poll_softirq+0xba/0x120 __do_softirq+0xba/0x4c0 irq_exit+0xbe/0xd0 smp_apic_timer_interrupt+0x38/0x50 apic_timer_interrupt+0x90/0xa0 </IRQ> RIP: srp_recv_done+0x450/0x6b0 [ib_srp] RSP: ffff88046f483e20 Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Israel Rukshin <israelr@mellanox.com> Cc: Max Gurtovoy <maxg@mellanox.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Steve Feeley <Steve.Feeley@sandisk.com> Cc: <stable@vger.kernel.org> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/ulp/srp/ib_srp.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 6e4467150049..a49289f600b1 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1892,9 +1892,11 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
complete(&ch->tsk_mgmt_done);
} else {
scmnd = scsi_host_find_tag(target->scsi_host, rsp->tag);
- if (scmnd) {
+ if (scmnd && scmnd->host_scribble) {
req = (void *)scmnd->host_scribble;
scmnd = srp_claim_req(ch, req, NULL, scmnd);
+ } else {
+ scmnd = NULL;
}
if (!scmnd) {
shost_printk(KERN_ERR, target->scsi_host,