From: Cristian Marussi <cristian.marussi@arm.com>
To: Benjamin Coddington <bcodding@redhat.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [aarch64] refcount_t: use-after-free in NFS with 64k pages
Date: Tue, 5 Feb 2019 12:10:33 +0000 [thread overview]
Message-ID: <e99fd27b-9e60-22fc-af6b-da93b0e0ca0f@arm.com> (raw)
In-Reply-To: <65CE8FC5-3ADB-4E61-8127-70B979B037A0@redhat.com>
Hi Ben
On 05/02/2019 11:53, Benjamin Coddington wrote:
> Hello Cristian and Punit,
>
> Did you ever get to the bottom of this one? We just saw this on one run
> of our 4.18.0-era ppc64le, and I'm wondering if we ever found the root
> cause.
unfortunately I stopped working actively on finding the root cause, since I've
found a viable workaround that let us unblock our broken LTP runs.
Setting wsize=65536 in NFS bootparams completely solves the issue with 64k pages
(and does NOT break 4k either :D): this confirmed my hyp that there is some sort
of race when accounting refcounts during the lifetime of nfs_page structs which
leads to a misscounted refcount...but as I said I never looked back into that
again (but never say never...)
Hope this helps...
Regards
Cristian
>
> Ben
>
next prev parent reply other threads:[~2019-02-05 12:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-19 14:48 [aarch64] refcount_t: use-after-free in NFS with 64k pages Cristian Marussi
2018-10-19 15:18 ` Punit Agrawal
2018-10-19 15:35 ` Cristian Marussi
2019-02-05 11:53 ` Benjamin Coddington
2019-02-05 12:10 ` Cristian Marussi [this message]
2019-02-05 12:14 ` Benjamin Coddington
2019-02-05 12:37 ` Cristian Marussi
2019-02-05 12:50 ` Cristian Marussi
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