Re: [PATCH 2/8] char: hpet: fix information leak to userland

From: Clemens Ladisch
Date: Mon Oct 18 2010 - 11:09:13 EST


Vasiliy Kulikov wrote:
> Structure info is copied to userland with some padding fields unitialized.
> It leads to leaking of stack memory.

> --- a/drivers/char/hpet.c
> +++ b/drivers/char/hpet.c
> @@ -581,6 +581,7 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,
> break;
> case HPET_INFO:
> {
> + memset(info, 0, sizeof(*info));
> if (devp->hd_ireqfreq)
> info->hi_ireqfreq =
> hpet_time_div(hpetp, devp->hd_ireqfreq);

This makes the following assignment "info->hi_ireqfreq = 0;" superfluous.


Regards,
Clemens
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