| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.3 014/344] sch_netem: fix a divide by zero in tabledist() | Date | Thu, 3 Oct 2019 17:49:39 +0200 |
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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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/sched/sch_netem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -777,7 +777,7 @@ static int get_dist_table(struct Qdisc * 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);
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