Re: [PATCH v2] staging: greybus: loopback_test: fix device-name leak

[Johan Hovold <johan@kernel.org>]

On Wed, Feb 22, 2017 at 12:36:23AM +0530, Gargi Sharma wrote:
> Change array index from the loop bound variable to loop index.
> Memory leak was occuring whenever there was more than one
> loopback device. The pointer to dirent structures must be
> individually freed before freeing the pointer array.
> 
> Coccinelle Script:
> @@
> expression arr,ex1,ex2;
> @@
> 
> for(ex1 = 0; ex1 < ex2; ex1++) { <...
>   arr[
> - ex2
> + ex1
>   ]
>   ...> }
> 
> Signed-off-by: Gargi Sharma <gs051095@gmail.com>
> ---
> Changes in v2:
> 	-Made the commit message clearer.
> ---
>  drivers/staging/greybus/tools/loopback_test.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/greybus/tools/loopback_test.c b/drivers/staging/greybus/tools/loopback_test.c
> index 18d7a3d..1c01833 100644
> --- a/drivers/staging/greybus/tools/loopback_test.c
> +++ b/drivers/staging/greybus/tools/loopback_test.c
> @@ -636,7 +636,7 @@ int find_loopback_devices(struct loopback_test *t)
>  	ret = 0;
>  done:
>  	for (i = 0; i < n; i++)
> -		free(namelist[n]);
> +		free(namelist[i]);
>  	free(namelist);
>  baddir:
>  	return ret;

Oh, there's an illegal free here, which probably was what Julia was
referring to. Yeah, not sure why things haven't blown up, perhaps there
happens to be NULL pointer after?

So we are in fact always leaking the device name here.

No need to resend, unless you prefer. You can add my Reviewed-by tag if
so.

Thanks,
Johan