From: Colin Ian King <colin.king@canonical.com>
Date: Sat, 13 Apr 2019 16:00:26 +0000 (+0100)
Subject: RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure
X-Git-Tag: v5.0.20~172
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=941198a0f9e84352969045b24c3c9462a3b1a359;p=thirdparty%2Fkernel%2Fstable.git

RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure

[ Upstream commit a6d2a5a92e67d151c98886babdc86d530d27111c ]

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: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 25a81fbb0d4d5..f1819b5272560 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -457,6 +457,8 @@ 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;