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Subject: Re: [PATCH] mm/gup: Fix memory leak in __gup_benchmark_ioctl
To:     Navid Emamdoost <navid.emamdoost@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Keith Busch <keith.busch@intel.com>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>
CC:     <emamd001@umn.edu>
References: <20191211174653.4102-1-navid.emamdoost@gmail.com>
From:   John Hubbard <jhubbard@nvidia.com>
Message-ID: <9a692d27-4654-f1fc-d4c5-c6efba02c8a9@nvidia.com>
Date:   Fri, 13 Dec 2019 13:40:15 -0800
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On 12/11/19 9:46 AM, Navid Emamdoost wrote:
> In the implementation of __gup_benchmark_ioctl() the allocated pages
> should be released before returning in case of an invalid cmd. Release
> pages via kvfree().
> 
> Fixes: 714a3a1ebafe ("mm/gup_benchmark.c: add additional pinning methods")
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---
>  mm/gup_benchmark.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c
> index 7dd602d7f8db..b160638f647e 100644
> --- a/mm/gup_benchmark.c
> +++ b/mm/gup_benchmark.c
> @@ -63,6 +63,7 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
>  					    NULL);
>  			break;
>  		default:
> +			kvfree(pages);
>  			return -1;
>  		}
>  

Hi,

The patch is correct, but I would like to second Ira's request for a ret value,
and a "goto done" to use a single place to kvfree, if you don't mind. 

Either way, you can add:

Reviewed-by: John Hubbard <jhubbard@nvidia.com>

thanks,
-- 
John Hubbard
NVIDIA