linux-kernel - Re: [PATCH v2] fs/buffer: add alert in try_to_free

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: <20251215-zuckungen-autogramm-a0c4291e525b@brauner>
Date: Mon, 15 Dec 2025 15:07:35 +0100
From: Christian Brauner <brauner@...nel.org>
To: jack@...e.cz,
	Deepakkumar Karn <dkarn@...hat.com>
Cc: Christian Brauner <brauner@...nel.org>,
	linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	viro@...iv.linux.org.uk
Subject: Re: [PATCH v2] fs/buffer: add alert in try_to_free_buffers() for folios without buffers

On Thu, 11 Dec 2025 18:42:11 +0530, Deepakkumar Karn wrote:
> try_to_free_buffers() can be called on folios with no buffers attached
> when filemap_release_folio() is invoked on a folio belonging to a mapping
> with AS_RELEASE_ALWAYS set but no release_folio operation defined.
> 
> In such cases, folio_needs_release() returns true because of the
> AS_RELEASE_ALWAYS flag, but the folio has no private buffer data. This
> causes try_to_free_buffers() to call drop_buffers() on a folio with no
> buffers, leading to a null pointer dereference.
> 
> [...]

Applied to the vfs-7.0.misc branch of the vfs/vfs.git tree.
Patches in the vfs-7.0.misc 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-7.0.misc

[1/1] fs/buffer: add alert in try_to_free_buffers() for folios without buffers
      https://git.kernel.org/vfs/vfs/c/b68f91ef3b3f