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From: Oleg Nesterov <oleg@redhat.com>
To: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Pu Lehui <pulehui@huaweicloud.com>,
	mhiramat@kernel.org, peterz@infradead.org,
	akpm@linux-foundation.org, Liam.Howlett@oracle.com,
	vbabka@suse.cz, jannh@google.com, pfalcato@suse.de,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	pulehui@huawei.com
Subject: Re: [RFC PATCH v2 1/2] mm/mremap: Fix uprobe anon page be overwritten when expanding vma during mremap
Date: Tue, 27 May 2025 17:52:54 +0200	[thread overview]
Message-ID: <20250527155253.GE8333@redhat.com> (raw)
In-Reply-To: <b16e6120-9f02-4a3a-8f85-394ea55bf516@lucifer.local>

On 05/27, Lorenzo Stoakes wrote:
>
> On Tue, May 27, 2025 at 05:30:08PM +0200, Oleg Nesterov wrote:
> >
> > >     struct perf_event_attr attr = {
> > >         .type = 9,
> >
> > Cough ;) Yes I too used perf_event_attr.type == 9 when I wrote another
> > test-case. Because I am lazy and this is what I see in
> > /sys/bus/event_source/devices/uprobe/type on my machine.
> >
> > But me should not assume that perf_pmu_register(&perf_uprobe) -> idr_alloc()
> > will return 9.
>
> While I agree we should probably try to do this nicely, in defence of Pu I think
> this is adapted from the syzkaller horror show :P and that code does tend to
> just insert random integers etc.

Not really ;)

syzkaller's reproducer reads /sys/bus/event_source/devices/uprobe/type, see
https://lore.kernel.org/all/20250521092503.3116340-1-pulehui@huaweicloud.com/

In any case. Many thanks to Lehui who investigated this problem!

Oleg.


  reply	other threads:[~2025-05-27 15:53 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-27 13:23 [RFC PATCH v2 0/2] Fix uprobe anon page be overwritten during mremap Pu Lehui
2025-05-27 13:23 ` [RFC PATCH v2 1/2] mm/mremap: Fix uprobe anon page be overwritten when expanding vma " Pu Lehui
2025-05-27 13:34   ` Lorenzo Stoakes
2025-05-27 15:17     ` Oleg Nesterov
2025-05-27 15:27       ` Lorenzo Stoakes
2025-05-27 15:29     ` Lorenzo Stoakes
2025-05-27 16:29     ` Pu Lehui
2025-05-27 14:23   ` Oleg Nesterov
2025-05-27 16:32     ` Pu Lehui
2025-05-27 16:37       ` Lorenzo Stoakes
2025-05-27 16:52         ` Pu Lehui
2025-05-27 17:20       ` Oleg Nesterov
2025-05-29 15:09         ` Pu Lehui
2025-05-29 15:12           ` Lorenzo Stoakes
2025-05-27 15:30   ` Oleg Nesterov
2025-05-27 15:33     ` Lorenzo Stoakes
2025-05-27 15:52       ` Oleg Nesterov [this message]
2025-05-27 16:41       ` Pu Lehui
2025-05-27 16:35     ` Pu Lehui
2025-05-27 13:23 ` [RFC PATCH v2 2/2] mm/mremap: Expose abnormal new_pte during move_ptes Pu Lehui
2025-05-27 14:24   ` Oleg Nesterov

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