From 62794fc4fbf52f2209dc094ea255eaef760e7d01 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 18 Sep 2019 16:24:12 -0700 Subject: [PATCH] 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: 8b4c3cdd9dd8 ("net: sched: Add policy validation for tc attributes") Reported-and-tested-by: syzbot+618aacd49e8c8b8486bd@syzkaller.appspotmail.com Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Reviewed-by: David Ahern Acked-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/sched/sch_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 1047825d9f48..81d58b280612 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -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 }, -- 2.30.2