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+618aacd49e8c8b848...@syzkaller.appspotmail.com
Cc: David Ahern <dsah...@gmail.com>
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Cc: Jiri Pirko <j...@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
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 },
--
2.21.0
