On Sat, 11 Jun 2016 03:33:08 +0200 Heinrich Schuchardt <xypron.g...@gmx.de>
wrote:
> An undetected overflow may occur in do_proc_dointvec_minmax_conv_param.
>
> ...
>
> --- 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;
hm.
What happens if someone does
echo -1 > /proc/foo
expecting to get 0xffffffff? That's a reasonable shorthand, and if we
change that to spit out EINVAL then people's stuff may break.
