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Subject: Re: general protection fault, probably for non-canonical address in
 nfsd
From:   Chuck Lever <chuck.lever@oracle.com>
In-Reply-To: <9727420.yF10LQ635x@xrated>
Date:   Mon, 8 Jun 2020 11:28:53 -0400
Cc:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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Message-Id: <2B6CBC8C-A1D4-4C39-AF45-958847C99572@oracle.com>
References: <15780697.tcFqIYE18H@xrated>
 <11558085.O9o76ZdvQC@linux-ws1.messinet.com> <9727420.yF10LQ635x@xrated>
To:     Hans-Peter Jansen <hpj@urpla.net>,
        Anthony Joseph Messina <amessina@messinet.com>
Sender: linux-nfs-owner@vger.kernel.org
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> On Jun 7, 2020, at 1:44 PM, Hans-Peter Jansen <hpj@urpla.net> wrote:
>=20
> Am Sonntag, 7. Juni 2020, 18:01:55 CEST schrieb Anthony Joseph =
Messina:
>> On Sunday, June 7, 2020 10:32:44 AM CDT Hans-Peter Jansen wrote:
>>> Hi,
>>>=20
>>> after upgrading the kernel from 5.6.11 to 5.6.14, we suffer from =
regular
>>> crashes of nfsd here:
>>>=20
>>> 2020-06-07T01:32:43.600306+02:00 server rpc.mountd[2664]: =
authenticated
>>> mount request from 192.168.3.16:303 for /work (/work)
>>> 2020-06-07T01:32:43.602594+02:00 server rpc.mountd[2664]: =
authenticated
>>> mount request from 192.168.3.16:304 for /work/vmware (/work)
>>> 2020-06-07T01:32:43.602971+02:00 server rpc.mountd[2664]: =
authenticated
>>> mount request from 192.168.3.16:305 for /work/vSphere (/work)
>>> 2020-06-07T01:32:43.606276+02:00 server kernel: [51901.089211] =
general
>>> protection fault, probably for non-canonical address =
0xb9159d506ba40000:
>>> 0000 [#1] SMP PTI 2020-06-07T01:32:43.606284+02:00 server kernel:
>>> [51901.089226] CPU: 1 PID: 3190 Comm: nfsd Tainted: G           O
>>> 5.6.14-lp151.2-default #1 openSUSE Tumbleweed (unreleased)
>>> 2020-06-07T01:32:43.606286+02:00 server kernel: [51901.089234] =
Hardware
>>> name: System manufacturer System Product Name/P7F-E, BIOS 0906
>>=20
>> I see similar issues in Fedora kernels 5.6.14 through 5.6.16
>> https://bugzilla.redhat.com/show_bug.cgi?id=3D1839287
>>=20
>> On the client I mount /home with sec=3Dkrb5p, and /mnt/koji with =
sec=3Dkrb5
>=20
> Thanks for confirmation.=20
>=20
> Apart from the hassle with server reboots, this issue has some DOS =
potential,=20
> I'm afraid.

If you have a reproducer (even a partial one) then bisecting between a
known good kernel and v5.6.14 (or 16) would be helpful.


--
Chuck Lever