[Bridge] [PATCH] net bridge: add null pointer check, fix panic

[Eric Dumazet]

On Thu, 2013-06-20 at 11:08 +0800, xiaoming gao wrote:
> From: newtongao <newtongao at tencent.com>
> Date: Wed, 19 Jun 2013 14:58:33 +0800
> Subject: [PATCH] net bridge: add null pointer check,fix panic
> 
> in kernel 3.0, br_port_get_rcu() may return NULL when network interface be deleting from bridge,
> but in function br_handle_frame and br_handle_local_finish, the pointer didn't be checked before using,
> so all br_port_get_rcu callers must do null check,or there occurs the null pointer panic.
> 
> kernel 3.4 also has this bug,i have verified.
> mainline kernel still did not  check br_port_get_rcu()'s NULL pointer, but i have not tested it yet.

Please check current version before sending a patch.

This was most probably fixed in commit 00cfec37484761a44
("net: add a synchronize_net() in netdev_rx_handler_unregister()")

Thanks