[PATCH] fix ZOMBIE state bug in PPPOE driver

Hi All,

I found a bug in kernel PPPOE driver.
When PPPOE is running over a virtual ethernet interface (e.g., a
bonding interface) and the user tries to delete the interface in case
the PPPOE state is ZOMBIE, the kernel will loop infinitely while
unregistering net_device for the reference count is not reset to zero
which should be done by dev_put().

The following patch could fix this issue:

$ git diff

diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c
index cbf7047..20f31d0 100644
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c

@@ -570,7 +570,7 @@ static int pppoe_release(struct socket *sock)

        po = pppox_sk(sk);

-       if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) {
+       if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND | PPPOX_ZOMBIE)) {
                dev_put(po->pppoe_dev);
                po->pppoe_dev = NULL;
        }

Thanks.

Regards,
Xiaodong Xu