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boundary="=-Q91RsiEvrT2A6vPIbGYO" User-Agent: Evolution 3.52.4 (3.52.4-1.fc40) MIME-Version: 1.0 X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: asmadeus@codewreck.org, linux-mm@kvack.org, marc.dionne@auristor.com, linux-afs@lists.infradead.org, pc@manguebit.com, linux-cifs@vger.kernel.org, Manu Bretelle , willy@infradead.org, smfrench@gmail.com, hsiangkao@linux.alibaba.com, idryomov@gmail.com, sprasad@microsoft.com, tom@talpey.com, ceph-devel@vger.kernel.org, ericvh@kernel.org, christian@brauner.io, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, v9fs@lists.linux.dev, jlayton@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, netfs@lists.linux.dev, linux-erofs@lists.ozlabs.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" --=-Q91RsiEvrT2A6vPIbGYO Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2024-09-23 at 23:33 +0100, David Howells wrote: > Eduard Zingerman wrote: >=20 > > - null-ptr-deref is triggered by access to page->pcp_list.next > > when list_del() is called from page_alloc.c:__rmqueue_pcplist(), >=20 > Can you tell me what the upstream commit ID of your kernel is? (before a= ny > patches are stacked on it) I used bpf-next tree, but could be reproduced with [1] as well, commit ID [2]. Decoded dmesg for this commit ID in [3]. [1] git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git [2] abf2050f51fd ("Merge tag 'media/v6.12-1' of git://git.kernel.org/pub/sc= m/linux/kernel/git/mchehab/linux-media") [3] https://gist.github.com/eddyz87/af39e04069c6ca30e66c3032c0384b8e > If you can modify your kernel, can you find the following in fs/netfs/: >=20 > buffered_read.c:127: new =3D kmalloc(sizeof(*new), GFP_NOFS); > buffered_read.c:353: folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL); > buffered_read.c:458: folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL); > misc.c:25: tail =3D kmalloc(sizeof(*tail), GFP_NOFS); >=20 > and change the kmalloc to kzalloc? No changes in behaviour. --=-Q91RsiEvrT2A6vPIbGYO Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable 
On Mon, 2024-09-23 at 23:33 +0=
100, David Howells wrote:
> Eduard Zingerman <eddyz87@gmail=
.com> wrote:
> 
> > - null-ptr-deref is tri=
ggered by access to page->pcp_list.next
> >   when list_=
del() is called from page_alloc.c:__rmqueue_pcplist(),
> 
> Can you tell me what the upstream commit ID of your kernel is?  =
(before any
> patches are stacked on it)

<=
pre>I used bpf-next tree, but could be reproduced with [1] as well,
commit ID [2]. Decoded dmesg for this commit ID in [3].

[1] git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.g=
it
[2] abf2050f51fd ("Merge tag 'media/v6.12-1' of git://git.kern=
el.org/pub/scm/linux/kernel/git/mchehab/linux-media")
[3] https:/=
/gist.github.com/eddyz87/af39e04069c6ca30e66c3032c0384b8e

> If you can modify your kernel, can you find the following in f=
s/netfs/:
> 
> buffered_read.c:127:			new =3D kma=
lloc(sizeof(*new), GFP_NOFS);
> buffered_read.c:353:	folioq =
=3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> buffered_read.c:45=
8:	folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> misc.c:2=
5:		tail =3D kmalloc(sizeof(*tail), GFP_NOFS);
> 
&g=
t; and change the kmalloc to kzalloc?

No changes i=
n behaviour.



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Message-ID: 
Subject: Re: [PATCH v2 19/25] netfs: Speed up buffered reading
From: Eduard Zingerman 
To: David Howells 
Cc: Manu Bretelle , asmadeus@codewreck.org, 
 ceph-devel@vger.kernel.org, christian@brauner.io, ericvh@kernel.org, 
 hsiangkao@linux.alibaba.com, idryomov@gmail.com, jlayton@kernel.org, 
 linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, 
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 v9fs@lists.linux.dev, willy@infradead.org
Date: Mon, 23 Sep 2024 16:37:58 -0700
In-Reply-To: <961634.1727130830@warthog.procyon.org.uk>
References: <0f6afef57196cb308aa90be5b06a64793aa24682.camel@gmail.com>
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	 <20240923183432.1876750-1-chantr4@gmail.com>
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On Mon, 2024-09-23 at 23:33 +0100, David Howells wrote:
> Eduard Zingerman  wrote:
>=20
> > - null-ptr-deref is triggered by access to page->pcp_list.next
> >   when list_del() is called from page_alloc.c:__rmqueue_pcplist(),
>=20
> Can you tell me what the upstream commit ID of your kernel is?  (before a=
ny
> patches are stacked on it)

I used bpf-next tree, but could be reproduced with [1] as well,
commit ID [2]. Decoded dmesg for this commit ID in [3].

[1] git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[2] abf2050f51fd ("Merge tag 'media/v6.12-1' of git://git.kernel.org/pub/sc=
m/linux/kernel/git/mchehab/linux-media")
[3] https://gist.github.com/eddyz87/af39e04069c6ca30e66c3032c0384b8e

> If you can modify your kernel, can you find the following in fs/netfs/:
>=20
> buffered_read.c:127:			new =3D kmalloc(sizeof(*new), GFP_NOFS);
> buffered_read.c:353:	folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> buffered_read.c:458:	folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> misc.c:25:		tail =3D kmalloc(sizeof(*tail), GFP_NOFS);
>=20
> and change the kmalloc to kzalloc?

No changes in behaviour.


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On Mon, 2024-09-23 at 23:33 +0=
100, David Howells wrote:
> Eduard Zingerman <eddyz87@gmail=
.com> wrote:
> 
> > - null-ptr-deref is tri=
ggered by access to page->pcp_list.next
> >   when list_=
del() is called from page_alloc.c:__rmqueue_pcplist(),
> 
> Can you tell me what the upstream commit ID of your kernel is?  =
(before any
> patches are stacked on it)

<=
pre>I used bpf-next tree, but could be reproduced with [1] as well,
commit ID [2]. Decoded dmesg for this commit ID in [3].

[1] git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.g=
it
[2] abf2050f51fd ("Merge tag 'media/v6.12-1' of git://git.kern=
el.org/pub/scm/linux/kernel/git/mchehab/linux-media")
[3] https:/=
/gist.github.com/eddyz87/af39e04069c6ca30e66c3032c0384b8e

> If you can modify your kernel, can you find the following in f=
s/netfs/:
> 
> buffered_read.c:127:			new =3D kma=
lloc(sizeof(*new), GFP_NOFS);
> buffered_read.c:353:	folioq =
=3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> buffered_read.c:45=
8:	folioq =3D kmalloc(sizeof(*folioq), GFP_KERNEL);
> misc.c:2=
5:		tail =3D kmalloc(sizeof(*tail), GFP_NOFS);
> 
&g=
t; and change the kmalloc to kzalloc?

No changes i=
n behaviour.



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