From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 62794fc4fbf52f2209dc094ea255eaef760e7d01 ]
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 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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 7b4270987ac16..637949b576c63 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1217,7 +1217,8 @@ 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 },