Re: [PATCH] i2c: busses: i2c-pxa.c: Fix for possible null pointer dereference

[Mateusz Guzik <mguzik-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Sat, May 17, 2014 at 07:14:08PM +0200, Rickard Strandqvist wrote:
> There is otherwise a risk of a possible null pointer dereference.
> 
> Was largely found by using a static code analysis program called cppcheck.
> 
> Signed-off-by: Rickard Strandqvist <rickard_strandqvist-IW2WV5XWFqGZkjO+N0TKoMugMpMbD5Xr@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-pxa.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index bbe6dfb..dbe5ebe 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -1269,7 +1269,9 @@ eremap:
>  eclk:
>  	kfree(i2c);
>  emalloc:
> -	release_mem_region(res->start, resource_size(res));
> +	if(res) {
> +		release_mem_region(res->start, resource_size(res));
> +	}
>  	return ret;
>  }
>  

This looks incorrect.

request_mem_region, which I believe is a prerequisite for this function
may not be called when you jump here.

-- 
Mateusz Guzik