linux-kernel - Re: [PATCH] buildid: validate page-backed file before parsing build ID

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] [day] [month] [year] [list]

Message-ID: <gkguoyowtzk2mtr264pgzh7xescgwhczjg4f6piuppnpebcgjb@atkroomgpyyk>
Date: Tue, 23 Dec 2025 11:05:49 -0800
From: Shakeel Butt <shakeel.butt@...ux.dev>
To: Jinchao Wang <wangjinchao600@...il.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>, Song Liu <song@...nel.org>, 
	Jiri Olsa <jolsa@...nel.org>, Alexei Starovoitov <ast@...nel.org>, 
	Daniel Borkmann <daniel@...earbox.net>, Andrii Nakryiko <andrii@...nel.org>, 
	Martin KaFai Lau <martin.lau@...ux.dev>, Eduard Zingerman <eddyz87@...il.com>, 
	Yonghong Song <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>, 
	KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>, 
	Hao Luo <haoluo@...gle.com>, linux-kernel@...r.kernel.org, bpf@...r.kernel.org, 
	syzbot+e008db2ac01e282550ee@...kaller.appspotmail.com
Subject: Re: [PATCH] buildid: validate page-backed file before parsing build
 ID

Hi Jinchao,

On Tue, Dec 23, 2025 at 06:32:07PM +0800, Jinchao Wang wrote:
> __build_id_parse() only works on page-backed storage.  Its helper paths
> eventually call mapping->a_ops->read_folio(), so explicitly reject VMAs
> that do not map a regular file or lack valid address_space operations.
> 
> Reported-by: syzbot+e008db2ac01e282550ee@...kaller.appspotmail.com
> Signed-off-by: Jinchao Wang <wangjinchao600@...il.com>

Check the previous discussion on this at
https://lore.kernel.org/all/20251114193729.251892-1-ssranevjti@gmail.com/

The preferred solution was to use kernel_read() call instead of adding
more such checks. Please check and test the patch at
https://lore.kernel.org/20251222205859.3968077-1-shakeel.butt@linux.dev/