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From: Clemens Ladisch <clemens@ladisch.de>
To: Vasiliy Kulikov <segooon@gmail.com>
Cc: kernel-janitors@vger.kernel.org,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Tejun Heo <tj@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/8] char: hpet: fix information leak to userland
Date: Mon, 18 Oct 2010 15:10:20 +0000	[thread overview]
Message-ID: <4CBC635C.6030500@ladisch.de> (raw)
In-Reply-To: <1287326477-7940-1-git-send-email-segooon@gmail.com>

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

WARNING: multiple messages have this Message-ID (diff)
From: Clemens Ladisch <clemens@ladisch.de>
To: Vasiliy Kulikov <segooon@gmail.com>
Cc: kernel-janitors@vger.kernel.org,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Tejun Heo <tj@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/8] char: hpet: fix information leak to userland
Date: Mon, 18 Oct 2010 17:10:20 +0200	[thread overview]
Message-ID: <4CBC635C.6030500@ladisch.de> (raw)
In-Reply-To: <1287326477-7940-1-git-send-email-segooon@gmail.com>

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

  reply	other threads:[~2010-10-18 15:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-17 14:41 [PATCH 2/8] char: hpet: fix information leak to userland Vasiliy Kulikov
2010-10-17 14:41 ` Vasiliy Kulikov
2010-10-18 15:10 ` Clemens Ladisch [this message]
2010-10-18 15:10   ` Clemens Ladisch

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