[PATCH] xt_socket: check sk before checking for netns.

From: Flavio Leitner
Date: Thu Sep 27 2018 - 18:36:28 EST


Only check for the network namespace if the socket is available.

Fixes: f564650106a6 ("netfilter: check if the socket netns is correct.")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Flavio Leitner <fbl@xxxxxxxxxx>
---
net/netfilter/xt_socket.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 0472f3472842..ada144e5645b 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -56,7 +56,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par,
struct sk_buff *pskb = (struct sk_buff *)skb;
struct sock *sk = skb->sk;

- if (!net_eq(xt_net(par), sock_net(sk)))
+ if (sk && !net_eq(xt_net(par), sock_net(sk)))
sk = NULL;

if (!sk)
@@ -117,7 +117,7 @@ socket_mt6_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
struct sk_buff *pskb = (struct sk_buff *)skb;
struct sock *sk = skb->sk;

- if (!net_eq(xt_net(par), sock_net(sk)))
+ if (sk && !net_eq(xt_net(par), sock_net(sk)))
sk = NULL;

if (!sk)
--
2.14.4