[PATCH AUTOSEL 4.9 19/19] sch_netem: fix a divide by zero in tabledist()
From: Sasha Levin <sashal@kernel.org>
Date: 2019-10-01 16:46:52
Also in:
lkml, stable
Subsystem:
netem network emulator, networking [general], tc subsystem, the rest · Maintainers:
Stephen Hemminger, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit b41d936b5ecfdb3a4abc525ce6402a6c49cffddc ]
syzbot managed to crash the kernel in tabledist() loading
an empty distribution table.
t = dist->table[rnd % dist->size];
Simply return an error when such load is attempted.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <redacted>
Signed-off-by: Jakub Kicinski <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sched/sch_netem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index e9812e21dbc9b..12e3ae09c4ba1 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c@@ -711,7 +711,7 @@ static int get_dist_table(struct Qdisc *sch, const struct nlattr *attr) int i; size_t s; - if (n > NETEM_DIST_MAX) + if (!n || n > NETEM_DIST_MAX) return -EINVAL; s = sizeof(struct disttable) + n * sizeof(s16);
--
2.20.1