linux-kernel - Re: [PATCH v2 3/3] alloc_tag: avoid warnings when freeing non-compound "tail" pages

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: <4429cad8-5363-4bd0-8b7a-36396d322464@gmail.com>
Date: Tue, 16 Sep 2025 21:47:58 +0100
From: Usama Arif <usamaarif642@...il.com>
To: Suren Baghdasaryan <surenb@...gle.com>, akpm@...ux-foundation.org
Cc: kent.overstreet@...ux.dev, vbabka@...e.cz, hannes@...xchg.org,
 shakeel.butt@...ux.dev, 00107082@....com, pasha.tatashin@...een.com,
 souravpanda@...gle.com, linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/3] alloc_tag: avoid warnings when freeing
 non-compound "tail" pages



On 15/09/2025 22:27, Suren Baghdasaryan wrote:
> When freeing "tail" pages of a non-compount high-order page, we properly
> subtract the allocation tag counters, however later when these pages are
> released, alloc_tag_sub() will issue warnings because tags for these pages
> are NULL.
> This issue was originally anticipated by Vlastimil in his review [1] and
> then recently reported by David.
> Prevent warnings by marking the tags empty.
> 
> [1] https://lore.kernel.org/all/6db0f0c8-81cb-4d04-9560-ba73d63db4b8@suse.cz/
> 
> Suggested-by: David Wang <00107082@....com>
> Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
> Acked-by: Shakeel Butt <shakeel.butt@...ux.dev>
> ---
>  mm/page_alloc.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 

Acked-by: Usama Arif <usamaarif642@...il.com>