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 C9096606A324 for ; Tue, 27 Oct 2026 20:32:31 +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=4rFQw4s3; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=cUUj8rbd 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=86fhQATGDo+8MDnZqTEUILQavbmG5W/eLVJguZT8p6Y=; b=4rFQw4s3tCMX+eEjYpgWvJT2iO cHOHhhaTum8L31Fin/P2bNbc/gvs3UdN6mbSd91710Uv1Zn5VHR38jEAANP4C1FdnpXtsTf3EGBev j22ZmYxFJM6c5fING5m/pU088wFk1r/pXdLXRIaMmmDAyIeZpT7DM1t/m6Sxi3wob9lwe6+1y8W9b Hw01yZhkXepOfS0ouLbGlW7FqFHQ9DTYNbbv12A9sWUTwdFqbuvjFg/j7himALS8s8oxJlyqOPic5 w6hm5MvPJBTTR7H/kYh3mXdurdbh1hithxwgEjZS3WWTfsGcwTq1C1drlFkC6Au04m35Gaad4V2ps Z1/SQAzQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLnqR-00000005jej-1iqB; Tue, 27 Oct 2026 20:32:31 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLnqQ-00000005jeY-2jGI for kexec@lists.infradead.org; Tue, 27 Oct 2026 20:32:30 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 20C2043075; Tue, 27 Oct 2026 20:32:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D5A11F01825; Tue, 27 Oct 2026 20:32:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793133150; bh=86fhQATGDo+8MDnZqTEUILQavbmG5W/eLVJguZT8p6Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=cUUj8rbdB8sxeJkMuDL4RCOdrYbrRplzvevKwnxFuwaEcH7HP+ENffudf2T0mpEpv 5IgYZPx4U8OILjqSgrQVM2ZVtEuU+s+iUCRqr37O0SlFEfCwYP6WH8sUr54mzsCt1s iMf6J0wk9xYuuAD3vV+C40mhUS8iHT1njIORZz73KfNOXA2HaiIMPxjzwaUpjzGq0a +HDzAe6Y83Ik9oMrM+EDzTEENc7lTwdaNWApON+amLO666KTk6vgqAwdt/I26Z5K2e tnFRDkmrRt4vDlqitIfQMOzf4AtEOnF0EKCtlUHfO8gpTP2ZD2//SXJTbcFDzwJNgN ttZ0nsquNOB0g== Date: Tue, 27 Oct 2026 20:32:28 +0000 From: Harry Yoo To: "David Hildenbrand (Arm)" 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 Subject: Re: [PATCH 43/46] mm/vma: don't leak the charge for stack growth Message-ID: References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-43-6f74bec9a5bb@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261027-fixes_core-v1-43-6f74bec9a5bb@kernel.org> 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=-11.2 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 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 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... -- Cheers, Harry / Hyeonggon