From: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Date: Mon, 12 Mar 2018 17:14:02 -0500
Subject: RDMA/core: Do not use invalid destination in determining port reuse
Patch-mainline: v4.16-rc7
Git-commit: 9dea9a2ff61c5efb4d4937ae23b14babd25a5547
References: bsc#1046306 FATE#322942

cma_port_is_unique() allows local port reuse if the quad (source
address and port, destination address and port) for this connection
is unique. However, if the destination info is zero or unspecified, it
can't make a correct decision but still allows port reuse. For example,
sometimes rdma_bind_addr() is called with unspecified destination and
reusing the port can lead to creating a connection with a duplicate quad,
after the destination is resolved. The issue manifests when MPI scale-up
tests hang after the duplicate quad is used.

Set the destination address family and add checks for zero destination
address and port to prevent source port reuse based on invalid destination.

Fixes: 19b752a19dce ("IB/cma: Allow port reuse for rdma_id")
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/cma.c |   12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3072,7 +3072,8 @@ static int cma_port_is_unique(struct rdm
 			continue;
 
 		/* different dest port -> unique */
-		if (!cma_any_port(cur_daddr) &&
+		if (!cma_any_port(daddr) &&
+		    !cma_any_port(cur_daddr) &&
 		    (dport != cur_dport))
 			continue;
 
@@ -3083,7 +3084,8 @@ static int cma_port_is_unique(struct rdm
 			continue;
 
 		/* different dst address -> unique */
-		if (!cma_any_addr(cur_daddr) &&
+		if (!cma_any_addr(daddr) &&
+		    !cma_any_addr(cur_daddr) &&
 		    cma_addr_cmp(daddr, cur_daddr))
 			continue;
 
@@ -3381,13 +3383,13 @@ int rdma_bind_addr(struct rdma_cm_id *id
 		}
 #endif
 	}
+	daddr = cma_dst_addr(id_priv);
+	daddr->sa_family = addr->sa_family;
+
 	ret = cma_get_port(id_priv);
 	if (ret)
 		goto err2;
 
-	daddr = cma_dst_addr(id_priv);
-	daddr->sa_family = addr->sa_family;
-
 	return 0;
 err2:
 	if (id_priv->cma_dev)