Re: [PATCH] net/ethoc: fix null dereference on error exit path

From: Max Filippov
Date: Sun May 22 2016 - 15:42:46 EST


Hi Colin,

On Sun, May 22, 2016 at 08:08:18PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> priv is assigned to NULL however all the error exit paths to label 'free'
> dereference priv, causing a null pointer dereference.
>
> Examination of the code shows that all error exits via the 'free'
> label path occur before priv is assigned to netdev_priv(netdev), hence
> there is no need to call clk_disable_unprepare and so the location of
> the label should be moved to free_netdev statement to avoid this null
> dereference on priv.

This description is a bit inaccurate. Indeed all 'goto free' above the
'priv = netdev_priv(netdev);' need to skip 'if (priv->clk)' check, but
there are two more 'goto free' below that line, and they look correct
now, but after this patch they'll leave the clock enabled.

--
Thanks.
-- Max