linux-kernel - Re: [PATCH v3 0/2] iterate_folioq bug when offset==size (Was: [REGRESSION] 9pfs issues on 6.12-rc1)

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20250815-scheckig-depesche-5de55f7855d1@brauner>
Date: Fri, 15 Aug 2025 16:16:33 +0200
From: Christian Brauner <brauner@...nel.org>
To: Dominique Martinet <asmadeus@...ewreck.org>
Cc: Christian Brauner <brauner@...nel.org>,
	Maximilian Bosch <maximilian@...sch.me>,
	Ryan Lahfa <ryan@...fa.xyz>,
	Christian Theune <ct@...ingcircus.io>,
	Arnout Engelen <arnout@...t.net>,
	linux-kernel@...r.kernel.org,
	linux-block@...r.kernel.org,
	linux-fsdevel@...r.kernel.org,
	stable@...r.kernel.org,
	"Matthew Wilcox (Oracle)" <willy@...radead.org>,
	David Howells <dhowells@...hat.com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH v3 0/2] iterate_folioq bug when offset==size (Was: [REGRESSION] 9pfs issues on 6.12-rc1)

On Wed, 13 Aug 2025 15:04:54 +0900, Dominique Martinet wrote:
> So we've had this regression in 9p for.. almost a year, which is way too
> long, but there was no "easy" reproducer until yesterday (thank you
> again!!)
> 
> It turned out to be a bug with iov_iter on folios,
> iov_iter_get_pages_alloc2() would advance the iov_iter correctly up to
> the end edge of a folio and the later copy_to_iter() fails on the
> iterate_folioq() bug.
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.fixes

[1/2] iov_iter: iterate_folioq: fix handling of offset >= folio size
      https://git.kernel.org/vfs/vfs/c/546a40359fd2
[2/2] iov_iter: iov_folioq_get_pages: don't leave empty slot behind
      https://git.kernel.org/vfs/vfs/c/334430b2d585