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| author | Jason Wang <jasowang@redhat.com> | 2019-05-08 23:20:17 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-05-09 09:21:42 -0700 |
| commit | a35d310f03a692bf4798eb309a1950a06a150620 (patch) | |
| tree | 2c660d427f4ad30a9cbd7c1bc73be07d5ba1664e /drivers/net/tun.c | |
| parent | 68a5cde9f02e690206e41c2d5aba88461a8829f1 (diff) | |
| download | linux-a35d310f03a692bf4798eb309a1950a06a150620.tar.gz linux-a35d310f03a692bf4798eb309a1950a06a150620.tar.bz2 linux-a35d310f03a692bf4798eb309a1950a06a150620.zip | |
tuntap: fix dividing by zero in ebpf queue selection
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>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 9d72f8c76c15..a52bd47e7aa2 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, |