[PATCH 3.12 69/72] rds: prevent dereference of a NULL device in rds_iw_laddr_check

[Jiri Slaby]

From: Sasha Levin <sasha.levin@xxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

[ Upstream commit bf39b4247b8799935ea91d90db250ab608a58e50 ]

Binding might result in a NULL device which is later dereferenced
without checking.

Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 net/rds/iw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/rds/iw.c b/net/rds/iw.c
index 7826d46baa70..589935661d66 100644
--- a/net/rds/iw.c
+++ b/net/rds/iw.c
@@ -239,7 +239,8 @@ static int rds_iw_laddr_check(__be32 addr)
 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 	/* due to this, we will claim to support IB devices unless we
 	   check node_type. */
-	if (ret || cm_id->device->node_type != RDMA_NODE_RNIC)
+	if (ret || !cm_id->device ||
+	    cm_id->device->node_type != RDMA_NODE_RNIC)
 		ret = -EADDRNOTAVAIL;
 
 	rdsdebug("addr %pI4 ret %d node type %d\n",
-- 
1.9.2

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