net/sched: act_gact: disallow 'goto chain' on fallback control action
in the following command:
# tc action add action <c1> random <rand_type> <c2> <rand_param>
'goto chain x' is allowed only for c1: setting it for c2 makes the kernel
crash with NULL pointer dereference, since TC core doesn't initialize the
chain handle.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index c89a7fa..b61c20e 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -88,6 +88,11 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla,
p_parm = nla_data(tb[TCA_GACT_PROB]);
if (p_parm->ptype >= MAX_RAND)
return -EINVAL;
+ if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) {
+ NL_SET_ERR_MSG(extack,
+ "goto chain not allowed on fallback");
+ return -EINVAL;
+ }
}
#endif