[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CA+55aFzxCjkSbfRUeX3W_oXSJ6LMUdRVYB=DR2b3rUNkiixM1A@mail.gmail.com>
Date: Thu, 28 Jun 2018 17:18:22 -0700
From: Linus Torvalds <torvalds@...ux-foundation.org>
To: Andrew Lutomirski <luto@...nel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
Thomas Gleixner <tglx@...utronix.de>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Linux API <linux-api@...r.kernel.org>,
Peter Zijlstra <peterz@...radead.org>,
Paul McKenney <paulmck@...ux.vnet.ibm.com>,
Boqun Feng <boqun.feng@...il.com>,
Dave Watson <davejwatson@...com>, Paul Turner <pjt@...gle.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Russell King - ARM Linux <linux@....linux.org.uk>,
Ingo Molnar <mingo@...hat.com>, Peter Anvin <hpa@...or.com>,
Andi Kleen <andi@...stfloor.org>,
Christoph Lameter <cl@...ux.com>, Ben Maurer <bmaurer@...com>,
Steven Rostedt <rostedt@...dmis.org>,
Josh Triplett <josh@...htriplett.org>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Michael Kerrisk <mtk.manpages@...il.com>, joelaf@...gle.com
Subject: Re: [RFC PATCH for 4.18 1/2] rseq: validate rseq_cs fields are < TASK_SIZE
On Thu, Jun 28, 2018 at 4:30 PM Andy Lutomirski <luto@...nel.org> wrote:
>
> The idea is that, if someone screws up and sticks a number like
> 0xbaadf00d00045678 into their rseq abort_ip in a 32-bit x86 program
> (when they actually mean 0x00045678), we want to something consistent.
I think the "something consistent" is perfectly fine with just "it won't work".
Make it do
if (rseq_cs->abort_ip != (unsigned long)rseq_cs->abort_ip)
return -EINVAL;
at abort time.
Done.
If it's a 32-bit kernel, the above will reject the thing, and if it's
a 64-bit kernel, it will be a no-op, but the abort won't work in a
32-bit caller.
Problem solved.
Linus
Powered by blists - more mailing lists