Date: Tue, 11 Jul 2017 16:10:53 +0100
From: Mark Rutland <mark.rutland@arm.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: linux-arm-kerne@lists.infradead.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-arch <linux-arch@vger.kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Morse <james.morse@arm.com>, Laura Abbott <labbott@redhat.com>,
        Russell King <linux@armlinux.org.uk>, stable <stable@vger.kernel.org>,
        steve.capper@arm.com, Will Deacon <will.deacon@arm.com>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH 0/2] Fatal signal handing within uaccess faults
Message-ID: <20170711151053.GG2681@leverpostej>
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On Tue, Jul 11, 2017 at 08:04:50AM -0700, Andy Lutomirski wrote:
> On Tue, Jul 11, 2017 at 7:16 AM, Mark Rutland <mark.rutland@arm.com> wrote:
> > Hi,
> >
> > Arch maintainer tl;dr: most arch fault code doesn't handle fatal signals
> > correctly, allowing unprivileged users to create an unkillable task which can
> > lock up the system. Please check whether your arch is affected.
> 
> I haven't tested for real, but brief inspection of the code suggests
> that x86 is okay.

AFAICT, yes.

As mentioned later on in the message, I beleive it's been ok since
commit:

  26178ec11ef3c6c8 ("x86: mm: consolidate VM_FAULT_RETRY handling")

... and my test-case didn't trigger anything in local testing on my
desktop.

Mark.