[PATCH 4.9 071/128] RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure

From: Greg Kroah-Hartman
Date: Wed May 29 2019 - 23:33:24 EST


[ 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@xxxxxxxxxxxxx>
Acked-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/infiniband/hw/cxgb4/cm.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index a2322b2dbd82c..e5752352e0fb1 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -455,6 +455,8 @@ 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;
--
2.20.1