net_sched: sch_skbprio: add message validation to skbprio_change()

Do not assume the attribute has the right size. Fixes: aea5f65 ("net/sched: add skbprio scheduler") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
mariux64 · May 3, 2020 · 2761121 · 2761121
1 parent dc30b40
commit 2761121
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/net/sched/sch_skbprio.c b/net/sched/sch_skbprio.c
@@ -169,6 +169,9 @@ static int skbprio_change(struct Qdisc *sch, struct nlattr *opt,
 {
 	struct tc_skbprio_qopt *ctl = nla_data(opt);
 
+	if (opt->nla_len != nla_attr_size(sizeof(*ctl)))
+		return -EINVAL;
+
 	sch->limit = ctl->limit;
 	return 0;
 }