RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure

commit a6d2a5a92e67d151c98886babdc86d530d27111c upstream.

Currently if alloc_skb fails to allocate the skb a null skb is passed to
t4_set_arp_err_handler and this ends up dereferencing the null skb.  Avoid
the NULL pointer dereference by checking for a NULL skb and returning
early.

Addresses-Coverity: ("Dereference null return")
Fixes: b38a0ad8ec11 ("RDMA/cxgb4: Set arp error handler for PASS_ACCEPT_RPL messages")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index bf488ae4dbe444e2b1f33ceb2dd1e89adf2eeb06..5faeb51be5c000803b5844b60d95ea9637a7a8f0 100644 (file)
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -346,6 +346,8 @@ static struct sk_buff *get_skb(struct sk_buff *skb, int len, gfp_t gfp)
                skb_reset_transport_header(skb);
        } else {
                skb = alloc_skb(len, gfp);
+               if (!skb)
+                       return NULL;
        }
        t4_set_arp_err_handler(skb, NULL, NULL);
        return skb;