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Re: [PATCH 1/2] lkdtm: fix memory leak of val

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On Tue, Apr 5, 2016 at 10:11 AM, Sudip Mukherjee
<sudipm.mukherjee@gmail.com> wrote:
> This case is supposed to read from a page after after it is freed, but
> it missed freeing val if we are not able to get a free page.
>
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
> ---
>  drivers/misc/lkdtm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
> index 5f1a36b..2f0b022 100644
> --- a/drivers/misc/lkdtm.c
> +++ b/drivers/misc/lkdtm.c
> @@ -498,12 +498,13 @@ static void lkdtm_do_action(enum ctype which)
>         }
>         case CT_READ_BUDDY_AFTER_FREE: {
>                 unsigned long p = __get_free_page(GFP_KERNEL);
> -               int saw, *val = kmalloc(1024, GFP_KERNEL);
> +               int saw, *val;
>                 int *base;
>
>                 if (!p)
>                         break;
>
> +               val = kmalloc(1024, GFP_KERNEL);

There's actually still a leak of "p" here, but I've fix that now too. Thanks!

-Kees

>                 if (!val)
>                         break;
>
> --
> 1.9.1
>



-- 
Kees Cook
Chrome OS & Brillo Security

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[PATCH 1/2] lkdtm: fix memory leak of val Sudip Mukherjee <sudipm.mukherjee@gmail.com> - 2016-04-05 19:20 +0200
  Re: [PATCH 1/2] lkdtm: fix memory leak of val Kees Cook <keescook@chromium.org> - 2016-04-07 00:50 +0200
  Re: [PATCH 1/2] lkdtm: fix memory leak of val Kees Cook <keescook@chromium.org> - 2016-04-07 01:00 +0200

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