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 syzkaller@googlegroups.com Signed-off-by: Jakub Kicinski jakub.kicinski@netronome.com 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 7acf1f2b8dfc3..2a431628af591 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -713,7 +713,7 @@ 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);