[alsa-devel] [PATCH] ASoC: Intel: Skylake: fix dereference before NULL check on ebus

[Dan Carpenter]

On Wed, Apr 19, 2017 at 01:16:13PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> ebus is being NULL checked however it is being dereferenced
> earlier on the assignment bus = ebus_to_hbus(ebus).  Fix this
> by moving the assignment to after the NULL check on ebus to
> avoid a NULL pointer dereference error.
> 

ebus_to_hbus() doesn't dereference "ebus" it just uses it for pointer
math.

#define ebus_to_hbus(ebus)      (&(ebus)->bus)

If you pass a NULL to there, it returns an offset starting from NULL but
it doesn't Oops.

regards,
dan carpenter