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authorBart Van Assche <bvanassche@acm.org>2014-05-20 15:03:49 +0200
committerBen Hutchings <ben@decadent.org.uk>2014-07-11 13:33:35 +0100
commitdc2f3db587e548df5fd55a8b420e18ac8c11cb8e (patch)
tree8c37f5dc67fd4451a084fe662409882a717c8e09
parent40b81e0d1a79c4770cc353bea225668a74e1493f (diff)
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IB/srp: Fix a sporadic crash triggered by cable pulling
commit 024ca90151f5e4296d30f72c13ff9a075e23c9ec upstream. Avoid that the loops that iterate over the request ring can encounter a pointer to a SCSI command in req->scmnd that is no longer associated with that request. If the function srp_unmap_data() is invoked twice for a SCSI command that is not in flight then that would cause ib_fmr_pool_unmap() to be invoked with an invalid pointer as argument, resulting in a kernel oops. Reported-by: Sagi Grimberg <sagig@mellanox.com> Reference: http://thread.gmane.org/gmane.linux.drivers.rdma/19068/focus=19069 Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/infiniband/ulp/srp/ib_srp.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 4ec049d..8770d44 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1353,6 +1353,12 @@ err_unmap:
err_iu:
srp_put_tx_iu(target, iu, SRP_IU_CMD);
+ /*
+ * Avoid that the loops that iterate over the request ring can
+ * encounter a dangling SCSI command pointer.
+ */
+ req->scmnd = NULL;
+
spin_lock_irqsave(&target->lock, flags);
list_add(&req->list, &target->free_reqs);