From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tty: vt_ioctl: fix potential Spectre v1
Date: Fri, 17 Aug 2018 12:07:55 +0100 [thread overview]
Message-ID: <20180817120755.1fcf8ccf@alans-desktop> (raw)
In-Reply-To: <20180816203038.GA14399@embeddedor.com>
On Thu, 16 Aug 2018 15:30:38 -0500
"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
> vsa.console is indirectly controlled by user-space, hence leading to
> a potential exploitation of the Spectre variant 1 vulnerability.
>
> This issue was detected with the help of Smatch:
>
> drivers/tty/vt/vt_ioctl.c:711 vt_ioctl() warn: potential spectre issue
> 'vc_cons' [r]
>
> Fix this by sanitizing vsa.console before using it to index vc_cons
>
> Notice that given that speculation windows are large, the policy is
> to kill the speculation on the first load and not worry if it can be
> completed with a dependent load/store [1].
>
> [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Alan
prev parent reply other threads:[~2018-08-17 11:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-16 20:30 [PATCH] tty: vt_ioctl: fix potential Spectre v1 Gustavo A. R. Silva
2018-08-17 11:07 ` Alan Cox [this message]
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