linux-kernel - Re: [Kernel Bug] WARNING in mempool_alloc

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: <aYIpVq-jTKyTQE8G@infradead.org>
Date: Tue, 3 Feb 2026 08:59:02 -0800
From: Christoph Hellwig <hch@...radead.org>
To: Vlastimil Babka <vbabka@...e.cz>
Cc: Christoph Hellwig <hch@...radead.org>, Harry Yoo <harry.yoo@...cle.com>,
	Vernon Yang <vernon2gm@...il.com>,
	李龙兴 <coregee2000@...il.com>,
	syzkaller@...glegroups.com, akpm@...ux-foundation.org,
	cl@...two.org, rientjes@...gle.com, roman.gushchin@...ux.dev,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [Kernel Bug] WARNING in mempool_alloc_noprof

On Tue, Feb 03, 2026 at 05:55:27PM +0100, Vlastimil Babka wrote:
> On 2/3/26 17:27, Christoph Hellwig wrote:
> > On Tue, Feb 03, 2026 at 06:52:39PM +0900, Harry Yoo wrote:
> >> Maybe the changelog could be rephrased a bit,
> >> but overall LGTM, thanks!
> > 
> > 
> > No, that does not make sense.  If mempool is used with __GFP_RECLAIM in
> > the flags it won't fail, and if it isn't, GFP_NOFAIL can't work.
> 
> So that means as long as there's __GFP_RECLAIM, __GFP_NOFAIL isn't wrong,
> just redundant.

Given how picky the rest of the mm is about __GFP_NOFAIL, silently
accepting it where it has no (or a weird and unexpected) effect
seems like a disservice to the users.