From: Jason Wang <jasowang@redhat.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: yuehaibing@huawei.com, xiyou.wangcong@gmail.com,
weiyongjun1@huawei.com, eric.dumazet@gmail.com,
Jason Wang <jasowang@redhat.com>
Subject: [PATCH net V3 1/2] tuntap: fix dividing by zero in ebpf queue selection
Date: Wed, 8 May 2019 23:20:17 -0400 [thread overview]
Message-ID: <1557372018-18544-1-git-send-email-jasowang@redhat.com> (raw)
We need check if tun->numqueues is zero (e.g for the persist device)
before trying to use it for modular arithmetic.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 96f84061620c6("tun: add eBPF based queue selection method")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index e9ca1c0..dc62fc3 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -596,13 +596,18 @@ static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
{
struct tun_prog *prog;
+ u32 numqueues;
u16 ret = 0;
+ numqueues = READ_ONCE(tun->numqueues);
+ if (!numqueues)
+ return 0;
+
prog = rcu_dereference(tun->steering_prog);
if (prog)
ret = bpf_prog_run_clear_cb(prog->prog, skb);
- return ret % tun->numqueues;
+ return ret % numqueues;
}
static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
--
1.8.3.1
next reply other threads:[~2019-05-09 3:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-09 3:20 Jason Wang [this message]
2019-05-09 3:20 ` [PATCH net V3 2/2] tuntap: synchronize through tfiles array instead of tun->numqueues Jason Wang
2019-05-09 11:42 ` weiyongjun (A)
2019-05-09 16:22 ` David Miller
2019-05-09 11:35 ` [PATCH net V3 1/2] tuntap: fix dividing by zero in ebpf queue selection Eric Dumazet
2019-05-09 16:22 ` David Miller
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