Commit 62794fc4 authored Sep 18, 2019 by Cong Wang Committed by Jakub Kicinski Sep 21, 2019

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: 8b4c3cdd ("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>

parent b0e1ee43

net/sched/sch_api.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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 },

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