From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794472183; b=v3OFupaoCEyL8aJoRfKTfL3uSq9RoKVOGiujn6bp+1N3vZuMjubvH2XTAGxELVZUDo2s pylDeFlNrGDx/K7xQdB/wb4pIULnxve75KVjCBNvxJlh8073r+Iph+28PJ2Q8NcIvVnOP o6gTdmjGsZw262vYl+3K5zCqXx0h3VeMjVkfWEiEUwD3Xi3Vi5bGZ6fyxuJYJ6kzzAHTo pDyJSGWa3f0AGFR2Rn5tYcBd1LrPmpoE3skBNe3bHW1p5XrzfAnhWnaCU4nE5VBWuVy+q h2Fi1mUMqFN8ppUZCT6MLhzfM7PyOzQvlUIL/x0k8iropzr0YVn8oNgBE3bJL3Yzlxg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794472183; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=LfFnO2mmUljHjiUSB+JHkBBNtfs+CR7s4DuaVxb5rYE=; b=P4dzZz/O+IFgMAmP+CHY49ethHLmPZtv5OIW+QUH4JJdMioX4hGkh31xodocVNMg/qSc fc0lm/M55w1nTBxskz67UTIN2pB9QjwRfmq3qv5vLvmqqeW1hqzY2j0W48rDR/NqCY0Pp exvh0oTWYUZzhUasNiYfP5phs6DQhDsLdJ2hpSy/TojeVTxyXqlNmLszCUXBBaRi8FDfN v4rasu31eNqHLXFogoe8cQJU0GFwfhhv4EvvJPvM/W3lWaDjNfXSonr7rpkDkp4amomEU fBW8Jh5onWONH/LepBuQPivAI0oq8WpjboR98TZoxmjgQ6oy6L7Kgb5MSVK+T2J6V8w== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nB63p4Uq; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D343606A31C; Thu, 12 Nov 2026 08:29:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nB63p4Uq Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16B3C1F00A05; Thu, 12 Nov 2026 08:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794472182; bh=LfFnO2mmUljHjiUSB+JHkBBNtfs+CR7s4DuaVxb5rYE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=nB63p4UqxR5h4UfW+jPSLXJ9RSk5E++eyt78k0yGCrFFQubEByGzJJTsvvAIcFmms OTd91A2zREUxuBnSe3GBaBsWFmJch5SNaIrRhdP/xzwh57B8zzy7AfoXpGmI76ENu6 oTY55ShnnxhYfEEtLsQZ2AzbAeWVeV+2Q3n8cu5/eNnbVZuJ1NSVreWqdCU2zfKDJH IbBVHqVWbvANm1i2jExZM1aLhezYUoJ/ECUS+v4TESKabMov/y/rV5pRxdbV2GlYxe czituN0+d4ncn6yOw5K51uDdaaGcC8gmRH9qbjHbi9ST1SQF6DLQ4j/0R8yJXvddbB TSIE6DH6AEPnw== Message-ID: <33b2549e-f033-42e5-82c4-a72cb0f92324@kernel.org> Date: Thu, 12 Nov 2026 09:29:35 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] mm/rmap: fix PTE table overruns during batched reference checks To: Baolin Wang , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Andrew Morton , Peter Xu , Lokesh Gidra , Barry Song , Rik van Riel , Harry Yoo , Jann Horn , Lance Yang , Ryan Roberts Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Chris Mason References: <20261111-pte_table_clamped_end-v1-0-2dbe339c487a@kernel.org> <20261111-pte_table_clamped_end-v1-3-2dbe339c487a@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/12/26 08:25, Baolin Wang wrote: > > > On 11/12/26 6:00 AM, David Hildenbrand (Arm) wrote: >> With a folded PMD, pmd_addr_end() simply returns the supplied end. >> folio_referenced_one() can therefore walk past the PTE table when >> checking references to a large folio. >> >> Folded PMDs are uncommon, but can occur even on arm64, for example >> with 64K pages and a 42-bit virtual address space. >> >> Use pte_table_clamped_end() to clamp the range to the PTE table and >> VMA boundaries. >> >> Fixes: 52e054f71840 ("mm: rmap: support batched checks of the references for >> large folios") >> Cc: stable@vger.kernel.org >> Reported-by: Chris Mason >> Signed-off-by: David Hildenbrand (Arm) >> --- > > LGTM. > Reviewed-by: Baolin Wang > > BTW, the 'end' calculation for the batch operation in lru_gen_look_around() > could also use the pte_table_clamped_end() helper. But this can be a follow-up. > > end = min(addr | ~PMD_MASK, vma->vm_end - 1) + 1; Cool, can you send a cleanup patch? I'd pick it up once these patches are upstream. I'll move these into core.git today, so you can send against that for-next later today. -- Cheers, David