linux-kernel - Re: [BUG] madvise05 leads kernel panic on 4.9.122

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: <20180821203631.GU12066@tassilo.jf.intel.com>
Date:   Tue, 21 Aug 2018 13:36:31 -0700
From:   Andi Kleen <ak@...ux.intel.com>
To:     yang.shi@...ux.alibaba.com
Cc:     David Woodhouse <dwmw2@...radead.org>, gregkh@...uxfoundation.org,
        tglx@...utronix.de, dave.hansen@...el.com, stable@...r.kernel.org,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [BUG] madvise05 leads kernel panic on 4.9.122

On Tue, Aug 21, 2018 at 01:30:20PM -0700, yang.shi@...ux.alibaba.com wrote:
> 
> 
> On 8/21/18 11:43 AM, David Woodhouse wrote:
> > On Tue, 2018-08-21 at 11:37 -0700, Yang Shi wrote:
> > > I just ran some regression test on stable 4.9.122 with LTP. madvise05
> > > triggers the below kernel panic:
> 
> Thanks, David. It works. A silly question, I don't get why this commit could
> solve this issue, it looks just like a code refactor. Just because it
> changed how to get pfn from page table entries? And, this may cause some
> mismatch on 4.9 stable without it?

With the L1TF patches open coded pte_val() to get the PFN can cause problems
because it doesn't do the invert for PROT_NONE mappings

The cleanup changes the open coded versions to use p*_pfn(), which always
works correctly.

-Andi