From: Eric Dumazet <edumazet@xxxxxxxxxx> [ 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@xxxxxxxxxx> Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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