net_sched: add max len check for TCA_KIND

The TCA_KIND attribute is of NLA_STRING which does not check
the NUL char. KMSAN reported an uninit-value of TCA_KIND which
is likely caused by the lack of NUL.

Change it to NLA_NUL_STRING and add a max len too.

Fixes: 8b4c3cdd9d ("net: sched: Add policy validation for tc attributes")
Reported-and-tested-by: syzbot+618aacd49e8c8b8486bd@syzkaller.appspotmail.com
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
This commit is contained in:
Cong Wang 2019-09-18 16:24:12 -07:00 committed by Jakub Kicinski
parent b0e1ee435a
commit 62794fc4fb

View File

@ -1390,7 +1390,8 @@ check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w)
}
const struct nla_policy rtm_tca_policy[TCA_MAX + 1] = {
[TCA_KIND] = { .type = NLA_STRING },
[TCA_KIND] = { .type = NLA_NUL_STRING,
.len = IFNAMSIZ - 1 },
[TCA_RATE] = { .type = NLA_BINARY,
.len = sizeof(struct tc_estimator) },
[TCA_STAB] = { .type = NLA_NESTED },