On Fri, Jun 10, 2016 at 6:33 PM, Heinrich Schuchardt <xypron.g...@gmx.de> wrote:
> An undetected overflow may occur in do_proc_dointvec_minmax_conv_param.
>
> Signed-off-by: Heinrich Schuchardt <xypron.g...@gmx.de>
Acked-by: Kees Cook <keesc...@chromium.org>
Thanks for the fix!
-Kees
> ---
> kernel/sysctl.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 35f0dcb..a9e7be3 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2313,7 +2313,17 @@ static int do_proc_dointvec_minmax_conv(bool *negp,
> unsigned long *lvalp,
> {
> struct do_proc_dointvec_minmax_conv_param *param = data;
> if (write) {
> - int val = *negp ? -*lvalp : *lvalp;
> + int val;
> +
> + if (*negp) {
> + if (*lvalp > (unsigned long) INT_MAX + 1)
> + return -EINVAL;
> + val = -*lvalp;
> + } else {
> + if (*lvalp > (unsigned long) INT_MAX)
> + return -EINVAL;
> + val = *lvalp;
> + }
> if ((param->min && *param->min > val) ||
> (param->max && *param->max < val))
> return -EINVAL;
> --
> 2.1.4
>
--
Kees Cook
Chrome OS & Brillo Security
