[ovs-dev] [PATCH] datapath: Fix RHEL compat for netdev_rx_handler_register

[Thomas Graf]

On Thu, Aug 15, 2013 at 12:33:06PM -0700, Chris Wright wrote:
> Andrei Andone reported an oops on CentOS 6.4 when adding a device to an
> ovs instance.  The problem is easy to reproduce and generates the
> following stack trace:
> 
> kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
> BUG: unable to handle kernel paging request at ffff88033afa49c0
> IP: [<ffff88033afa49c0>] 0xffff88033afa49c0
> ...
> Call Trace:
>  <IRQ>
>  [<ffffffff814487ba>] ? __netif_receive_skb+0x60a/0x750
>  [<ffffffff81055f96>] ? enqueue_task+0x66/0x80
>  [<ffffffff8144aa38>] netif_receive_skb+0x58/0x60
>  [<ffffffff8144ab40>] napi_skb_finish+0x50/0x70
>  [<ffffffff8144d0e9>] napi_gro_receive+0x39/0x50
>  [<ffffffffa025f46c>] igb_poll+0x7ec/0xc70 [igb]
>  [<ffffffff810e6881>] ? cpu_quiet_msk+0xc1/0x130
> ...
> 
> As you can see, we jumped to data rather than code.  This is caused by
> a mistake in the compat code for netdev_rx_handler_register which sets
> the handler to rx_handler_data rather than rx_handler.  This was
> introduced by commit "3e35fe3 datapath: rhel: Move RHEL OVS hook
> registration to netdev_rx_handler_register() backport".
> 
> Reported-by: Andrei Andone <andrei.andone at softvision.ro>
> Signed-off-by: Chris Wright <chrisw at sous-sol.org>
> Cc: Thomas Graf <tgraf at redhat.com>
> Cc: Pravin Shelar <pshelar at nicira.com>

Reviewed-by: Thomas Graf <tgraf at redhat.com>

Thanks for fixing this slip Chris