[PATCH] RDMA/cxgb4: add null-ptr-check after ip_dev_find()

[Nikita Zhandarovich]

ip_dev_find() may return NULL and assign it to pdev which is
dereferenced later.
Fix this by checking the return value of ip_dev_find() for NULL
similar to the way it is done with other instances of said function.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 1cab775c3e75 ("RDMA/cxgb4: Fix LE hash collision bug for passive open connection")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx>
---
 drivers/infiniband/hw/cxgb4/cm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index c16017f6e8db..07d0bafb7ac5 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -4151,6 +4151,10 @@ static int rx_pkt(struct c4iw_dev *dev, struct sk_buff *skb)
 
 	if (neigh->dev->flags & IFF_LOOPBACK) {
 		pdev = ip_dev_find(&init_net, iph->daddr);
+		if (!pdev) {
+			pr_err("%s - failed to find device!\n", __func__);
+			goto free_dst;
+		}
 		e = cxgb4_l2t_get(dev->rdev.lldi.l2t, neigh,
 				    pdev, 0);
 		pi = (struct port_info *)netdev_priv(pdev);
-- 
2.25.1