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From: Peilin Ye <yepeilin.cs@gmail.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	dri-devel <dri-devel@lists.freedesktop.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [Linux-kernel-mentees] [PATCH] drm/bufs: Prevent kernel-infoleak in copy_one_buf()
Date: Tue, 28 Jul 2020 07:15:27 -0400	[thread overview]
Message-ID: <20200728111527.GA407693@PWN> (raw)
In-Reply-To: <CAK8P3a29=CugbGtZRQc0abGXvexp=gBk+LwOCG3yNCPakup+NQ@mail.gmail.com>

On Tue, Jul 28, 2020 at 10:11:09AM +0200, Arnd Bergmann wrote:
> On Tue, Jul 28, 2020 at 3:45 AM Peilin Ye <yepeilin.cs@gmail.com> wrote:
> >
> > copy_one_buf() is copying uninitialized stack memory to userspace due to
> > the compiler not initializing holes in statically allocated structures.
> > Fix it by initializing `v` with memset().
> 
> I would add 'potentially' somewhere in that description: it is architecture
> dependent whether there are holes in this structure as 'enum' types
> and 'long' are both dependent on the ABI, and even if there is a hole,
> it is undefined behavior whether the hold gets initialized.

I see. I will fix that up. Thank you for the advice!

Peilin Ye

> Other than that, the patch looks good.
> 
> > Cc: stable@vger.kernel.org
> > Fixes: 5c7640ab6258 ("switch compat_drm_infobufs() to drm_ioctl_kernel()")
> > Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> 
> Acked-by: Arnd Bergmann <arnd@arndb.de>

  reply	other threads:[~2020-07-28 11:15 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28  1:43 [Linux-kernel-mentees] [PATCH] drm/bufs: Prevent kernel-infoleak in copy_one_buf() Peilin Ye
2020-07-28  8:11 ` Arnd Bergmann
2020-07-28 11:15   ` Peilin Ye [this message]
2020-07-28 11:52 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-07-28 12:35   ` David Laight
2020-07-28 12:50     ` Peilin Ye

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