From: Andrew Morton <akpm@linux-foundation.org>
To: Peter Xu <peterx@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Nadav Amit <nadav.amit@gmail.com>,
David Hildenbrand <david@redhat.com>,
syzbot+d8426b591c36b21c750e@syzkaller.appspotmail.com
Subject: Re: [PATCH] mm/userfaultfd: Reset ptes when close() for wr-protected ones
Date: Mon, 22 Apr 2024 12:47:19 -0700 [thread overview]
Message-ID: <20240422124719.5097e42a736403d306ba7cf0@linux-foundation.org> (raw)
In-Reply-To: <20240422133311.2987675-1-peterx@redhat.com>
On Mon, 22 Apr 2024 09:33:11 -0400 Peter Xu <peterx@redhat.com> wrote:
> Userfaultfd unregister includes a step to remove wr-protect bits from all
> the relevant pgtable entries, but that only covered an explicit
> UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover
> that too.
We should include a description of the userspace-visible effects of the
bug, please. Always.
I see it triggers a WARN, but so what - why ca't we simply delete the
WARN statement if that's the only effect? Presumably there are other
consequences - what are they?
Also, a WARN-triggering bug should be fixed in -stable kernels so we'll
need a FIXES:, please?
next prev parent reply other threads:[~2024-04-22 19:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-22 13:33 Peter Xu
2024-04-22 15:09 ` David Hildenbrand
2024-04-22 19:47 ` Andrew Morton [this message]
2024-04-22 21:08 ` Peter Xu
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