linux-kernel - Re: [PATCH 2/2] lkdtm: fix memory leak of base

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Date:	Wed, 6 Apr 2016 15:49:20 -0700
From:	Kees Cook <keescook@...omium.org>
To:	Sudip Mukherjee <sudipm.mukherjee@...il.com>
Cc:	Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] lkdtm: fix memory leak of base

On Tue, Apr 5, 2016 at 10:11 AM, Sudip Mukherjee
<sudipm.mukherjee@...il.com> wrote:
> This case is supposed to read from a memory after it has been freed,
> but we missed freeing base if the memory 'val' could not be allocated.
>
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@...ethink.co.uk>

Also applied. Thanks!

-Kees

> ---
>  drivers/misc/lkdtm.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
> index 2f0b022..5b3a63c 100644
> --- a/drivers/misc/lkdtm.c
> +++ b/drivers/misc/lkdtm.c
> @@ -458,8 +458,10 @@ static void lkdtm_do_action(enum ctype which)
>                         break;
>
>                 val = kmalloc(len, GFP_KERNEL);
> -               if (!val)
> +               if (!val) {
> +                       kfree(base);
>                         break;
> +               }
>
>                 *val = 0x12345678;
>                 base[offset] = *val;
> --
> 1.9.1
>



-- 
Kees Cook
Chrome OS & Brillo Security