net: sched: act_tunnel_key: fix NULL pointer dereference during init

Metadata pointer is only initialized for action TCA_TUNNEL_KEY_ACT_SET, but
it is unconditionally dereferenced in tunnel_key_init() error handler.
Verify that metadata pointer is not NULL before dereferencing it in
tunnel_key_init error handling code.

Fixes: ee28bb56ac5b ("net/sched: fix memory leak in act_tunnel_key_init()")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 8b43fe0..3f943de 100644 (file)
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -377,7 +377,8 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
        return ret;
 
 release_tun_meta:
-       dst_release(&metadata->dst);
+       if (metadata)
+               dst_release(&metadata->dst);
 
 err_out:
        if (exists)