[PATCH] [net/sched] Fix null pointer deref skb in tc_ctl_action

[Gaurav Singh]

Add null check for skb

Signed-off-by: Gaurav Singh <gaurav1...@gmail.com>
---
 net/sched/act_api.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 8ac7eb0a8309..fd584821d75a 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -1473,9 +1473,12 @@ static const struct nla_policy tcaa_policy[TCA_ROOT_MAX 
+ 1] = {
 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
                         struct netlink_ext_ack *extack)
 {
+       if (!skb)
+               return 0;
+
        struct net *net = sock_net(skb->sk);
        struct nlattr *tca[TCA_ROOT_MAX + 1];
-       u32 portid = skb ? NETLINK_CB(skb).portid : 0;
+       u32 portid = NETLINK_CB(skb).portid;
        int ret = 0, ovr = 0;
 
        if ((n->nlmsg_type != RTM_GETACTION) &&
-- 
2.17.1