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From: Arnd Bergmann <arnd@arndb.de>
To: Peilin Ye <yepeilin.cs@gmail.com>
Cc: "Mauro Carvalho Chehab" <mchehab@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
	"Hans Verkuil" <hverkuil-cisco@xs4all.nl>,
	"Sakari Ailus" <sakari.ailus@linux.intel.com>,
	"Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
	"Vandana BN" <bnvandana@gmail.com>,
	"Ezequiel Garcia" <ezequiel@collabora.com>,
	"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	"Linux Media Mailing List" <linux-media@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [Linux-kernel-mentees] [PATCH v3] media/v4l2-core: Fix kernel-infoleak in video_put_user()
Date: Mon, 27 Jul 2020 09:25:16 +0200	[thread overview]
Message-ID: <CAK8P3a3NB2BVo9fH-Wcinrhhs-QJ=9dK59Ds83TvgLmEkRy3qA@mail.gmail.com> (raw)
In-Reply-To: <20200726222703.102701-1-yepeilin.cs@gmail.com>

On Mon, Jul 27, 2020 at 12:28 AM Peilin Ye <yepeilin.cs@gmail.com> wrote:
>
> video_put_user() is copying uninitialized stack memory to userspace due
> to the compiler not initializing holes in the structures declared on the
> stack. Fix it by initializing `ev32` and `vb32` using memset().
>
> Reported-and-tested-by: syzbot+79d751604cb6f29fbf59@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?extid=79d751604cb6f29fbf59
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>

Thanks a lot for addressing this! I now see that I actually created a similar
bugfix for it back in January, but for some reason that got stuck in my
backlog and I never wrote a proper description for it or sent it out to the
list, sorry about that. I would hope we could find a way to have either
the compiler or sparse warn if we copy uninitialized data to user space,
but we now don't even check for that within the kernel any more.

I would suggest adding these tags to the patch, to ensure it gets backported
to stable kernels as needed:

Cc: stable@vger.kernel.org
Fixes: 1a6c0b36dd19 ("media: v4l2-core: fix VIDIOC_DQEVENT for time64 ABI")
Fixes: 577c89b0ce72 ("media: v4l2-core: fix v4l2_buffer handling for
time64 ABI")

In addition to

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

  reply	other threads:[~2020-07-27  7:25 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-26 16:44 [Linux-kernel-mentees] [PATCH] media/v4l2-core: Fix kernel-infoleak in video_put_user() Peilin Ye
2020-07-26 17:30 ` Laurent Pinchart
2020-07-26 18:07   ` Peilin Ye
2020-07-26 22:08     ` Laurent Pinchart
2020-07-26 22:15       ` Peilin Ye
2020-07-26 18:12   ` Peilin Ye
2020-07-26 22:05 ` [Linux-kernel-mentees] [PATCH v2] " Peilin Ye
2020-07-26 22:10   ` Laurent Pinchart
2020-07-26 22:16     ` Peilin Ye
2020-07-26 22:27   ` [Linux-kernel-mentees] [PATCH v3] " Peilin Ye
2020-07-27  7:25     ` Arnd Bergmann [this message]
2020-07-27  7:56       ` Peilin Ye
2020-07-27 13:16       ` Dan Carpenter
2020-07-27 14:05         ` Arnd Bergmann
2020-07-27 14:14           ` Peilin Ye
2020-07-27 14:20             ` Arnd Bergmann
2020-07-27 14:46             ` Dan Carpenter
2020-07-27 15:30               ` Peilin Ye
2020-07-27 14:43           ` Dan Carpenter
2020-07-27 14:55             ` Arnd Bergmann
2020-07-27 22:04         ` Peilin Ye
2020-07-28  9:00           ` Arnd Bergmann
2020-07-28 10:02           ` Dan Carpenter
2020-07-28 12:22         ` Linus Walleij
2020-07-28 13:06           ` Dan Carpenter
2020-07-28 13:58             ` Arnd Bergmann
2020-07-30  8:07               ` Bartosz Golaszewski
2020-07-30  8:15                 ` Arnd Bergmann
2020-07-30  8:38                   ` Andy Shevchenko
2020-07-30  9:18                     ` Arnd Bergmann
2020-07-30 11:48                       ` Andy Shevchenko
2020-07-30 13:49                         ` Arnd Bergmann
2020-07-27  8:00     ` [Linux-kernel-mentees] [PATCH v4] " Peilin Ye

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