Re: [PATCH] pstore: use memdup_user

[Kees Cook]

On Fri, Apr 28, 2017 at 6:45 PM, Geliang Tang <geliangtang@xxxxxxxxx> wrote:
> Use memdup_user() helper instead of open-coding to simplify the code.
>
> Signed-off-by: Geliang Tang <geliangtang@xxxxxxxxx>

Thanks! Applied for -next.

-Kees

> ---
>  fs/pstore/platform.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 43b3ca5..903e0fe 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -640,19 +640,16 @@ static int pstore_write_user_compat(struct pstore_record *record,
>         if (record->buf)
>                 return -EINVAL;
>
> -       record->buf = kmalloc(record->size, GFP_KERNEL);
> -       if (!record->buf)
> -               return -ENOMEM;
> -
> -       if (unlikely(copy_from_user(record->buf, buf, record->size))) {
> -               ret = -EFAULT;
> +       record->buf = memdup_user(buf, record->size);
> +       if (unlikely(IS_ERR(record->buf))) {
> +               ret = PTR_ERR(record->buf);
>                 goto out;
>         }
>
>         ret = record->psi->write(record);
>
> -out:
>         kfree(record->buf);
> +out:
>         record->buf = NULL;
>
>         return unlikely(ret < 0) ? ret : record->size;
> --
> 2.9.3
>



-- 
Kees Cook
Pixel Security