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From: Andrew Morton <akpm@linux-foundation.org>
To: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: aarcange@redhat.com, surenb@google.com, david@redhat.com,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails
Date: Thu, 22 Feb 2024 13:00:05 -0800	[thread overview]
Message-ID: <20240222130005.c3f24eed1c1a27c66947e9df@linux-foundation.org> (raw)
In-Reply-To: <20240222080815.46291-1-zhengqi.arch@bytedance.com>

On Thu, 22 Feb 2024 16:08:15 +0800 Qi Zheng <zhengqi.arch@bytedance.com> wrote:

> After ptep_clear_flush(), if we find that src_folio is pinned we will fail
> UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to
> src_folio->{mapping,index} is not restored in this process. This is not
> what we expected, so fix it.
> 
> Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")

What are the expected worst-case userspace-visible runtime effects of
this flaw?


  parent reply	other threads:[~2024-02-22 21:00 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-22  8:08 Qi Zheng
2024-02-22  8:43 ` David Hildenbrand
2024-02-22 21:41   ` Suren Baghdasaryan
2024-02-22 21:00 ` Andrew Morton [this message]
2024-02-22 21:56   ` Suren Baghdasaryan
2024-02-28 10:46     ` David Hildenbrand

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