diff options
| author | Jason Wang | 2013-06-05 16:44:57 +0800 |
|---|---|---|
| committer | David S. Miller | 2013-06-10 14:32:47 -0700 |
| commit | 92bb73ea2c434618a68a58a2f3a5c3fd0b660d18 (patch) | |
| tree | 3b310ab023ab438175bd2aa0ccf71814e3760ae9 /drivers | |
| parent | 4364d5f96eed7994a2c625bd9216656e55fba0cb (diff) | |
tuntap: fix a possible race between queue selection and changing queues
Complier may generate codes that re-read the tun->numqueues during
tun_select_queue(). This may be a race if vlan->numqueues were changed in the
same time and can lead unexpected result (e.g. very huge value).
We need prevent the compiler from generating such codes by adding an
ACCESS_ONCE() to make sure tun->numqueues were only read once.
Bug were introduced by commit c8d68e6be1c3b242f1c598595830890b65cea64a
(tuntap: multiqueue support).
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/tun.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 89776c592151..b1cbfbcff789 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -352,7 +352,7 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb) u32 numqueues = 0; rcu_read_lock(); - numqueues = tun->numqueues; + numqueues = ACCESS_ONCE(tun->numqueues); txq = skb_get_rxhash(skb); if (txq) { |