From: Michael Ellerman <mpe@ellerman.id.au>
To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: oss-security@lists.openwall.com,
"debian-powerpc@lists.debian.org"
<debian-powerpc@lists.debian.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: Linux kernel: powerpc: KVM guest can trigger host crash on Power8
Date: Wed, 27 Oct 2021 22:06:28 +1100 [thread overview]
Message-ID: <874k92bubv.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <04864fe5-fdd0-74b2-2bad-0303e4c2b15a@physik.fu-berlin.de>
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> writes:
> Hi Michael!
>
> On 10/27/21 07:30, Michael Ellerman wrote:
>> I did test the repro case you gave me before (in the bugzilla), which
>> was building glibc, that passes for me with a patched host.
>
> Did you manage to crash the unpatched host?
Yes, the parallel builds of glibc you described crashed the unpatched
host 100% reliably for me.
I also have a standalone reproducer I'll send you.
> If the unpatched host crashes for you but the patched doesn't, I will
> make sure I didn't accidentally miss anything.
OK thanks.
> Also, I'll try a kernel from git with Debian's config.
>
>> I guess we have yet another bug.
>>
>> I tried the following in a debian BE VM and it completed fine:
>>
>> $ dget -u http://ftp.debian.org/debian/pool/main/g/git/git_2.33.1-1.dsc
>> $ sbuild -d sid --arch=powerpc --no-arch-all git_2.33.1-1.dsc
>>
>> Same for ppc64.
>>
>> And I also tried both at once, repeatedly in a loop.
>
> Did you try building gcc-11 for powerpc and ppc64 both at once?
No, I will try that now.
>> I guess it's something more complicated.
>>
>> What exact host/guest kernel versions and configs are you running?
>
> Both the host and guest are running Debian's stock 5.14.12 kernel. The host has
> a kernel with your patches applied, the guest doesn't.
OK that sounds fine.
I tested upstream stable v5.14.13 + my patches, but there's nothing
betwen 5.14.12 and 5.14.13 that should matter AFAICS.
> Let me do some more testing.
Thanks.
cheers
next prev parent reply other threads:[~2021-10-27 11:07 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 11:18 Linux kernel: powerpc: KVM guest can trigger host crash on Power8 Michael Ellerman
2021-10-26 8:48 ` John Paul Adrian Glaubitz
2021-10-27 5:29 ` Nicholas Piggin
2021-10-27 5:30 ` Michael Ellerman
2021-10-27 10:03 ` John Paul Adrian Glaubitz
2021-10-27 11:06 ` Michael Ellerman [this message]
2021-10-27 11:09 ` John Paul Adrian Glaubitz
2021-10-28 6:39 ` Michael Ellerman
2021-10-28 11:20 ` John Paul Adrian Glaubitz
2021-10-28 14:05 ` John Paul Adrian Glaubitz
2021-10-28 14:15 ` John Paul Adrian Glaubitz
2021-11-01 17:36 ` Michal Suchánek
2021-10-29 0:41 ` Nicholas Piggin
2021-10-29 12:33 ` John Paul Adrian Glaubitz
2021-11-01 17:43 ` Michal Suchánek
2021-10-30 7:19 ` John Paul Adrian Glaubitz
2021-11-01 6:53 ` Michael Ellerman
2021-11-01 7:37 ` John Paul Adrian Glaubitz
2021-11-01 17:20 ` John Paul Adrian Glaubitz
2022-01-04 13:00 ` John Paul Adrian Glaubitz
2022-01-06 10:58 ` Michael Ellerman
2022-01-07 11:20 ` John Paul Adrian Glaubitz
2022-01-09 22:17 ` John Paul Adrian Glaubitz
2022-01-13 0:17 ` John Paul Adrian Glaubitz
2022-01-26 20:21 ` John Paul Adrian Glaubitz
2022-01-27 15:50 ` Mike
2021-10-28 13:52 ` John Paul Adrian Glaubitz
2021-10-28 14:00 ` John Paul Adrian Glaubitz
2021-10-28 3:58 ` [oss-security] " Salvatore Bonaccorso
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