From: Colin Ian King <colin.king@canonical.com>
Date: Fri, 23 Mar 2018 23:51:57 +0000 (+0000)
Subject: net: qualcomm: rmnet: check for null ep to avoid null pointer dereference
X-Git-Tag: v4.19~1326^2~94
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0c29ba1b43df1eb7d8beb03fc929d2dac4c15f7e;p=platform%2Fkernel%2Flinux-rpi.git

net: qualcomm: rmnet: check for null ep to avoid null pointer dereference

The call to rmnet_get_endpoint can potentially return NULL so check
for this to avoid any subsequent null pointer dereferences on a NULL
ep.

Detected by CoverityScan, CID#1465385 ("Dereference null return value")

Fixes: 23790ef12082 ("net: qualcomm: rmnet: Allow to configure flags for existing devices")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
index 38d9356..d339885 100644
--- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
+++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c
@@ -312,6 +312,8 @@ static int rmnet_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (data[IFLA_RMNET_MUX_ID]) {
 		mux_id = nla_get_u16(data[IFLA_RMNET_MUX_ID]);
 		ep = rmnet_get_endpoint(port, priv->mux_id);
+		if (!ep)
+			return -ENODEV;
 
 		hlist_del_init_rcu(&ep->hlnode);
 		hlist_add_head_rcu(&ep->hlnode, &port->muxed_ep[mux_id]);