linux-kernel - [PATCH AUTOSEL 5.10 63/85] net: sched: tapr: prevent cycle_time == 0 in parse_taprio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed,  5 May 2021 12:36:26 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Du Cheng <ducheng2@...il.com>,
        syzbot+d50710fd0873a9c6b40c@...kaller.appspotmail.com,
        Cong Wang <cong.wang@...edance.com>,
        "David S . Miller" <davem@...emloft.net>,
        Sasha Levin <sashal@...nel.org>, netdev@...r.kernel.org
Subject: [PATCH AUTOSEL 5.10 63/85] net: sched: tapr: prevent cycle_time == 0 in parse_taprio_schedule

From: Du Cheng <ducheng2@...il.com>

[ Upstream commit ed8157f1ebf1ae81a8fa2653e3f20d2076fad1c9 ]

There is a reproducible sequence from the userland that will trigger a WARN_ON()
condition in taprio_get_start_time, which causes kernel to panic if configured
as "panic_on_warn". Catch this condition in parse_taprio_schedule to
prevent this condition.

Reported as bug on syzkaller:
https://syzkaller.appspot.com/bug?extid=d50710fd0873a9c6b40c

Reported-by: syzbot+d50710fd0873a9c6b40c@...kaller.appspotmail.com
Signed-off-by: Du Cheng <ducheng2@...il.com>
Acked-by: Cong Wang <cong.wang@...edance.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 net/sched/sch_taprio.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index c966c05a0be9..00853065dfa0 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -900,6 +900,12 @@ static int parse_taprio_schedule(struct taprio_sched *q, struct nlattr **tb,
 
 		list_for_each_entry(entry, &new->entries, list)
 			cycle = ktime_add_ns(cycle, entry->interval);
+
+		if (!cycle) {
+			NL_SET_ERR_MSG(extack, "'cycle_time' can never be 0");
+			return -EINVAL;
+		}
+
 		new->cycle_time = cycle;
 	}
 
-- 
2.30.2