| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.2 62/63] sch_netem: fix a divide by zero in tabledist() | Date | Tue, 1 Oct 2019 12:41:24 -0400 |
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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 b17f2ed970e29..f5cb35e550f8d 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -777,7 +777,7 @@ static int get_dist_table(struct Qdisc *sch, struct disttable **tbl, struct disttable *d; int i; - if (n > NETEM_DIST_MAX) + if (!n || n > NETEM_DIST_MAX) return -EINVAL; d = kvmalloc(sizeof(struct disttable) + n * sizeof(s16), GFP_KERNEL); -- 2.20.1
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