linux-kernel - Re: [PATCH 0/1] Fix zero copy I/O on __get_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250508112443.49ff0414@sarc.samsung.com>
Date: Thu, 8 May 2025 11:24:43 +0300
From: Pantelis Antoniou <p.antoniou@...tner.samsung.com>
To: Andrew Morton <akpm@...ux-foundation.org>
CC: <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>, Artem Krupotkin
	<artem.k@...sung.com>, Charles Briere <c.briere@...sung.com>, "Wade
 Farnsworth" <wade.farnsworth@...mens.com>
Subject: Re: [PATCH 0/1] Fix zero copy I/O on __get_user_pages allocated
 pages

On Wed, 7 May 2025 14:50:18 -0700
Andrew Morton <akpm@...ux-foundation.org> wrote:

> On Wed, 7 May 2025 10: 41: 04 -0500 Pantelis Antoniou <p. antoniou@
> partner. samsung. com> wrote: > Updates to network filesystems
> enabled zero copy I/O by using the > netfslib common accessors.
> Updates by whom? Are all the people who 
> On Wed, 7 May 2025 10:41:04 -0500 Pantelis Antoniou
> <p.antoniou@...tner.samsung.com> wrote:
> 
> > Updates to network filesystems enabled zero copy I/O by using the
> > netfslib common accessors.
> 
> Updates by whom?  Are all the people who need to know about this being
> cc'ed here?
> 

I think the first cover letter contains that information.

> > One example of that is the 9p filesystem which is commonly used in
> > qemu based setups for sharing files with the host.
> > 
> > In our emulation environment we have noticed failing writes when
> > performing I/O from a userspace mapped DRM GEM buffer object.
> > The platform does not use VRAM, all graphics memory is regular DRAM
> > memory, allocated via __get_free_pages
> 
> We should identify which kernel version(s) should be patched, please. 
> 6.16-rc1?  6.15?  -stable?
> 

The first occurance of the bug was on internal kernel tree that was
based on 6.8.

This patch is against 6.15-rc5.

> I often make these decisions but in this case I have far too little
> information to be able to do that.
> 

No worries.

I see that this is picked up for mm unstable as is? Do you want
me to generate a single patch merging the info of the cover letter
and the single patch?

The reason for the split is that I was not sure if you needed to
have all the sordid details included in the applied patch.

FWIW, we also have a buildroot patch that exhibits the problem
in a much simplified way that what the original bug report came about.
I don't think its appropriate content for the list, but I can
share if anyone is curious about it.

> Thanks.

Regards

-- Pantelis