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Subject: Re: [PATCH] ASoC: Intel: Skylake: fix dereference before NULL check
 on ebus
To: Dan Carpenter <dan.carpenter@oracle.com>
References: <20170419121613.12353-1-colin.king@canonical.com>
 <20170419133249.ac3sdmn7kqjbxaii@mwanda>
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From: Colin Ian King <colin.king@canonical.com>
Message-ID: <fa93c146-cb7b-cefa-75d3-6507c63200c5@canonical.com>
Date: Wed, 19 Apr 2017 14:34:33 +0100
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On 19/04/17 14:32, Dan Carpenter wrote:
> On Wed, Apr 19, 2017 at 01:16:13PM +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@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.

Doh, brown paper bag moment for me.

> 
> regards,
> dan carpenter
> 
>