From: Matthew Wilcox <willy@infradead.org>
To: "David Hildenbrand (Arm)" <david@kernel.org>
Cc: ZhengYuan Huang <gality369@gmail.com>,
akpm@linux-foundation.org, ljs@kernel.org,
Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org,
surenb@google.com, mhocko@suse.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, baijiaju1990@gmail.com,
r33s3n6@gmail.com, zzzccc427@gmail.com
Subject: Re: [PATCH] mm: prepare anon_vma before swapin rmap
Date: Fri, 17 Apr 2026 14:03:04 +0100 [thread overview]
Message-ID: <aeIviKEdw-52J7JY@casper.infradead.org> (raw)
In-Reply-To: <fb80d953-93de-4ce3-80c6-15cd53dd956f@kernel.org>
On Fri, Apr 17, 2026 at 01:57:59PM +0200, David Hildenbrand (Arm) wrote:
> On 4/17/26 12:53, David Hildenbrand (Arm) wrote:
> > On 4/17/26 03:16, ZhengYuan Huang wrote:
> >> [BUG]
> >> madvise(MADV_HWPOISON) can fault a swap entry back in through
> >> get_user_pages_fast() and hit:
...
> >> I can reproduce this issue deterministically on v6.18, but I have not
> >> been able to reproduce it with the same setup on next-20260415.
>
> Just speculating, we had
>
> commit 3b617fd3d317bf9dd7e2c233e56eafef05734c9d
> Author: Lorenzo Stoakes <ljs@kernel.org>
> Date: Mon Jan 5 20:11:49 2026 +0000
>
> mm/vma: enforce VMA fork limit on unfaulted,faulted mremap merge too
>
> Go into v6.19.
>
> Maybe there was a scenario where we could have lost vma->anon_vma during
> a merge, resulting in a swapped page in an anon_vma.
>
> If this cannot be reproduced on 6.19+,there is nothing to worry about.
... except that 6.18 is LTS so we need a fix for that kernel version.
And maybe 6.12 as well (a373baed5a9d went into 6.9, so no need to
go further back than that)
next prev parent reply other threads:[~2026-04-17 13:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-17 1:16 ZhengYuan Huang
2026-04-17 4:03 ` Matthew Wilcox
2026-04-17 10:53 ` David Hildenbrand (Arm)
2026-04-17 11:57 ` David Hildenbrand (Arm)
2026-04-17 13:03 ` Matthew Wilcox [this message]
2026-04-17 13:36 ` Vlastimil Babka (SUSE)
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