net/sched: cls_flower: Properly handle classifier flags dumping

Dump the classifier flags only if non zero and make sure to check
the return status of the handler that puts them into the netlink msg.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 0826c8ec3a768ed1ea1ea313b2a00b8be6b1bd88..850d98294bf60c104a0c2d2a219ae31e7d566a0e 100644 (file)
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1229,7 +1229,8 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
        if (fl_dump_key_flags(skb, key->control.flags, mask->control.flags))
                goto nla_put_failure;
 
-       nla_put_u32(skb, TCA_FLOWER_FLAGS, f->flags);
+       if (f->flags && nla_put_u32(skb, TCA_FLOWER_FLAGS, f->flags))
+               goto nla_put_failure;
 
        if (tcf_exts_dump(skb, &f->exts))
                goto nla_put_failure;