From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 844EF606A321 for ; Wed, 28 Oct 2026 08:18:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=LeVAwIDN; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=izn1ZkeJ DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=rfg1cZlJEwCYeHTThqQx/kzAjyEawogFMalQMObgNNs=; b=LeVAwIDNsW0/0z CLC2WFPLXs8nPgCzc1PNhKdRPs9OehSGA+bpTBDxVjbcuknWjskMF/gEcmi8AYc21u0q4WhpTC8Z0 /nuYlcmGijp/j+9WJpE8H5imTJh+oFL2Sk+fIGNeIxk6syO1M5tIb+rkTdAMqBE6mAA7krAHHIwkx KXBCZSrCTWbmjOFwULYBhD322VHBcQCpzd0P/SQw+IYmUurXIxZPmCFNg5/UdtxL0fz0DmBQ0e4Le JH+/ELGw6EUHk25VwF9AiEF3AVFJRZDXWD5reopBXbizac5AmsdWQiM4oU6FOF+X34KrGVxa/c0cz PT70aonEONCqmaOXtYJw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLyri-00000006WbS-15JN; Wed, 28 Oct 2026 08:18:34 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLyrh-00000006WbF-33Ve for kexec@lists.infradead.org; Wed, 28 Oct 2026 08:18:33 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 7E80E600CB; Wed, 28 Oct 2026 08:18:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE98A1F01825; Wed, 28 Oct 2026 08:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793175512; bh=rfg1cZlJEwCYeHTThqQx/kzAjyEawogFMalQMObgNNs=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=izn1ZkeJiAVyrZlZw/L12WrwvmU9O9TkhkIMYNeFuVV3QwF+dw6E6BnNte8AiawuX V4xa+DjVJZXhwb5An4LGNvsgrUubDnomzrscpG6wexo/M14K7qD7WbjYWr1SfVEaTd AMkXsm0mtFAhikKH3fvL5DsiOpBnOYXnOslQmQLqvPGzEO+Fzs5Jel7RNmnq/bYJFW wzwgIjUhuSDrcUKqPEirYiuau8fXKzIffDyoMU2KiJUhvgXXCjqI2ADqU4XbpQD0Tn pYDUfJZhkBy630Bqk8DYa2RyUOuVUbSxoXiHNg6m5Poej1wzj+GJCLIhuEFesgWzl1 NnCJrrGyNgccw== Message-ID: <7193e4ee-c5c7-456d-91f8-ef6f465f9803@kernel.org> Date: Wed, 28 Oct 2026 09:18:14 +0100 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 43/46] mm/vma: don't leak the charge for stack growth To: Harry Yoo Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, stable@vger.kernel.org, Josef Bacik References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-43-6f74bec9a5bb@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-12.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/27/26 21:32, Harry Yoo wrote: > On Tue, Oct 27, 2026 at 12:18:03AM +0100, David Hildenbrand (Arm) wrote: >> acct_stack_growth() charges stack expansion even without VM_ACCOUNT. >> This can happen for read-only or MAP_NORESERVE mappings created with >> MAP_GROWSDOWN. Unmapping these VMAs does not release the charge, leaking >> Committed_AS. >> >> Only check and charge growth for VM_ACCOUNT VMAs, matching mremap(). >> Unaccounted growth skips the overcommit check while remaining subject >> to the other stack-growth limits. >> >> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >> Cc: stable@vger.kernel.org >> Reported-by: Josef Bacik >> Reviewed-by: Lorenzo Stoakes (ARM) >> Signed-off-by: David Hildenbrand (Arm) >> --- > > Looks good to me, > Reviewed-by: Harry Yoo (Meta) > > Maybe worth having a warning when it's accounting w/o VMA_ACCOUNT_BIT > or let those helpers skip when there's no VMA_ACCOUNT_BIT set... You mean passing the VMA instead of the MM? -- Cheers, David