linux-kernel - Re: [PATCH] alloc_tag: Handle incomplete bulk allocations in vm_module_tags

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: <CABdmKX3D-iCwkuAXLsFyyJD7LikoR0rygR6CnR4Fv-u9+OjnZg@mail.gmail.com>
Date: Wed, 9 Apr 2025 14:51:18 -0700
From: "T.J. Mercier" <tjmercier@...gle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Suren Baghdasaryan <surenb@...gle.com>, Kent Overstreet <kent.overstreet@...ux.dev>, 
	Janghyuck Kim <janghyuck.kim@...sung.com>, linux-mm@...ck.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] alloc_tag: Handle incomplete bulk allocations in vm_module_tags_populate

On Wed, Apr 9, 2025 at 2:11 PM Andrew Morton <akpm@...ux-foundation.org> wrote:
>
> On Wed, 9 Apr 2025 14:08:48 -0700 Andrew Morton <akpm@...ux-foundation.org> wrote:
>
> > On Wed,  9 Apr 2025 19:54:47 +0000 "T.J. Mercier" <tjmercier@...gle.com> wrote:
> >
> > > alloc_pages_bulk_node may partially succeed and allocate fewer than the
> > > requested nr_pages. There are several conditions under which this can
> > > occur, but we have encountered the case where CONFIG_PAGE_OWNER is
> > > enabled causing all bulk allocations to always fallback to single page
> > > allocations due to commit 187ad460b841 ("mm/page_alloc: avoid page
> > > allocator recursion with pagesets.lock held").
> > >
> > > Currently vm_module_tags_populate immediately fails when
> > > alloc_pages_bulk_node returns fewer than the requested number of pages.
> > > This patch causes vm_module_tags_populate to retry bulk allocations for
> > > the remaining memory instead.
> >
> > Please describe the userspace-visible runtime effects of this change.  In a way
> > which permits a user who is experiencing some problem can recognize that this
> > patch will address that problem.
> >
> > ...
> >
> > Reported-by: Janghyuck Kim <janghyuck.kim@...sung.com>
>
> A Closes: link will presumably help with the above info.  checkpatch
> now warns about the absence of a Closes:

Hi Andrew, This was reported on our internal bug tracker so there is
no public link I can provide here. If it's better not to add a
Reported-by in this case, then I will do that in the future.