linux-kernel - Re: perf: perf_fuzzer quickly locks up on 4.15-rc7

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.21.1801111542160.23914@macbook-air>
Date:   Thu, 11 Jan 2018 15:43:41 -0500 (EST)
From:   Vince Weaver <vincent.weaver@...ne.edu>
To:     Vince Weaver <vincent.weaver@...ne.edu>
cc:     Peter Zijlstra <peterz@...radead.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andy Lutomirski <luto@...nel.org>
Subject: Re: perf: perf_fuzzer quickly locks up on 4.15-rc7

On Thu, 11 Jan 2018, Vince Weaver wrote:

> On Thu, 11 Jan 2018, Peter Zijlstra wrote:
> 
> > On Thu, Jan 11, 2018 at 01:21:12PM -0600, Josh Poimboeuf wrote:
> > > Yuck.  This time it was stack recursion on the entry stack.  In the
> > > previous error, recursion was detected on the IRQ stack.  Otherwise they
> > > look quite similar.
> > > 
> > > Was that also with nopti?
> > 
> > Both with pti enabled, nopti makes things work again.
> 
> I think I have hit those errors even with pti disabled but now I'll have 
> to double check.

I can confirm this, I am able to trigger the stack recursion warning even 
when "pti=off" is set.

Jan 11 15:34:47 core2 kernel: [  320.668900] WARNING: stack recursion on stack type 4
Jan 11 15:34:47 core2 kernel: [  320.668909] WARNING: can't dereference registers at 00000000d5ae0491 for ip swapgs_restore_regs_and_return_to_usermode+0x28/0x7c

Vince