Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7;
From:   Oleksandr Natalenko <oleksandr@natalenko.name>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     linux-kernel@vger.kernel.org, Bagas Sanjaya <bagasdotme@gmail.com>,
        linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org,
        dri-devel@lists.freedesktop.org,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Christian =?ISO-8859-1?Q?K=F6nig?= <christian.koenig@amd.com>,
        Linux Regressions <regressions@lists.linux.dev>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org
Subject: Re: [REGRESSION] BUG: KFENCE: memory corruption in
 drm_gem_put_pages+0x186/0x250
Date:   Mon, 02 Oct 2023 17:38:48 +0200
Message-ID: <2160215.irdbgypaU6@natalenko.name>
In-Reply-To: <ZRrUjcWqtmzPV3Fs@casper.infradead.org>
References: <13360591.uLZWGnKmhe@natalenko.name> <2300189.ElGaqSPkdT@natalenko.name>
 <ZRrUjcWqtmzPV3Fs@casper.infradead.org>
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="nextPart13361251.uLZWGnKmhe";
 micalg="pgp-sha256"; protocol="application/pgp-signature"
Precedence: bulk

--nextPart13361251.uLZWGnKmhe
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="UTF-8"; protected-headers="v1"
From: Oleksandr Natalenko <oleksandr@natalenko.name>
To: Matthew Wilcox <willy@infradead.org>
Date: Mon, 02 Oct 2023 17:38:48 +0200
Message-ID: <2160215.irdbgypaU6@natalenko.name>
In-Reply-To: <ZRrUjcWqtmzPV3Fs@casper.infradead.org>
MIME-Version: 1.0

On pond=C4=9Bl=C3=AD 2. =C5=99=C3=ADjna 2023 16:32:45 CEST Matthew Wilcox w=
rote:
> On Mon, Oct 02, 2023 at 01:02:52PM +0200, Oleksandr Natalenko wrote:
> > > > > > BUG: KFENCE: memory corruption in drm_gem_put_pages+0x186/0x250
> > > > > >=20
> > > > > > Corrupted memory at 0x00000000e173a294 [ ! ! ! ! ! ! ! ! ! ! ! =
! ! ! ! ! ] (in kfence-#108):
> > > > > >  drm_gem_put_pages+0x186/0x250
> > > > > >  drm_gem_shmem_put_pages_locked+0x43/0xc0
> > > > > >  drm_gem_shmem_object_vunmap+0x83/0xe0
> > > > > >  drm_gem_vunmap_unlocked+0x46/0xb0
> > > > > >  drm_fbdev_generic_helper_fb_dirty+0x1dc/0x310
> > > > > >  drm_fb_helper_damage_work+0x96/0x170
> >=20
> > Matthew, before I start dancing around, do you think ^^ could have the =
same cause as 0b62af28f249b9c4036a05acfb053058dc02e2e2 which got fixed by 8=
63a8eb3f27098b42772f668e3977ff4cae10b04?
>=20
> Yes, entirely plausible.  I think you have two useful points to look at
> before delving into a full bisect -- 863a8e and the parent of 0b62af.
> If either of them work, I think you have no more work to do.

OK, I've did this against v6.5.5:

```
git log --oneline HEAD~3..
7c1e7695ca9b8 (HEAD -> test) Revert "mm: remove struct pagevec"
8f2ad53b6eac6 Revert "mm: remove check_move_unevictable_pages()"
fa1e3c0b5453c Revert "drm: convert drm_gem_put_pages() to use a folio_batch"
```

then rebooted the host multiple times, and the issue is not seen any more.

So I guess 3291e09a463870610b8227f32b16b19a587edf33 is the culprit.

Thanks.

=2D-=20
Oleksandr Natalenko (post-factum)
--nextPart13361251.uLZWGnKmhe
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: This is a digitally signed message part.
Content-Transfer-Encoding: 7Bit

-----BEGIN PGP SIGNATURE-----
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=38a+
-----END PGP SIGNATURE-----

--nextPart13361251.uLZWGnKmhe--