[PATCH net 1/2] net_sched: reject unknown tcfa_action values

[Paolo Abeni]

After the commit 802bfb19152c ("net/sched: user-space can't set
unknown tcfa_action values"), unknown tcfa_action values are
converted to TC_ACT_UNSPEC, but the common agreement is instead
rejecting such configurations.

This change also introduce an helper to simplify the destruction
of a single action, avoding code duplication.

Fixes: 802bfb19152c ("net/sched: user-space can't set unknown tcfa_action 
values")
Signed-off-by: Paolo Abeni <pab...@redhat.com>
---
 net/sched/act_api.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index db83dac1e7f4..8614f2c282e8 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -662,6 +662,13 @@ int tcf_action_destroy(struct tc_action *actions[], int 
bind)
        return ret;
 }
 
+int tcf_action_destroy_one(struct tc_action *a, int bind)
+{
+       struct tc_action *actions[] = { a, NULL };
+
+       return tcf_action_destroy(actions, bind);
+}
+
 static int tcf_action_put(struct tc_action *p)
 {
        return __tcf_action_put(p, false);
@@ -881,17 +888,16 @@ struct tc_action *tcf_action_init_1(struct net *net, 
struct tcf_proto *tp,
        if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
                err = tcf_action_goto_chain_init(a, tp);
                if (err) {
-                       struct tc_action *actions[] = { a, NULL };
-
-                       tcf_action_destroy(actions, bind);
                        NL_SET_ERR_MSG(extack, "Failed to init TC action 
chain");
+                       tcf_action_destroy_one(a, bind);
                        return ERR_PTR(err);
                }
        }
 
        if (!tcf_action_valid(a->tcfa_action)) {
                NL_SET_ERR_MSG(extack, "invalid action value, using 
TC_ACT_UNSPEC instead");
-               a->tcfa_action = TC_ACT_UNSPEC;
+               tcf_action_destroy_one(a, bind);
+               return ERR_PTR(-EINVAL);
        }
 
        return a;
-- 
2.17.1