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 C3523606A321 for ; Fri, 30 Oct 2026 03:42:26 +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=fC/6w0I1; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=cuzNSJ3N DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=B0Ll3KZd/2ziMYeiGgscSMDWwXvufGTqPOd/mun6tfo=; b=fC/6w0I17DodBwrRObVDtsSXAt h/aCF3T8S9j5uopVQpWlur/Ro9eBjimdjvZoW6DI1vvsxj4TylPbN6P+UvZLHFhBdF8109q7IpaKB RA7Vyq3hdatYTXYClbZjLJDN/TahdLqyvvMkPU96H1rG3moIhddyF5KRXYXHjnSEllwM0zfiomDB0 W5XzrfbECgjW/WMq4r+hSJ4qBvYLJ0ddAfWwxY4PLUHwq411sXHGiH/dCGSwY1oa6HEbIDxkNoLMq GBdW11nEAxOZNGfYYVRF8xsAqE0A6eFtYSOIr0VtPBBpzKmxHcZc/ie5ltkvbTdkSzCzUmbOH9ts+ n6UfQMGg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdVa-0000000Al6k-0AcO; Fri, 30 Oct 2026 03:42:26 +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 1xMdVY-0000000Al5R-1rdi for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:42:24 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 287F3413CF; Fri, 30 Oct 2026 03:42:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 427211F000C1; Fri, 30 Oct 2026 03:42:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331744; bh=B0Ll3KZd/2ziMYeiGgscSMDWwXvufGTqPOd/mun6tfo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=cuzNSJ3NAD2t26YEqiHWiBiFIhGhFPzM5af5XTYo/oFLZIZr2pNySGhB6P9W+OXjk QNWpy1yfl3O9iPo9+UAradfy7hFUgd4/yte0UX8nM/hmzjs36F8V1XB3C2Ls7Lb9p2 GtLrWybBwuB1p83Aowa4Lkb44O02T9vJt/ARCE/q5KOicuYiyZtDapSlln60HlDj8t eMa06EKf29456OP6F3V8XgWIRBSVRJs+1WiiTrKlz/uCKeOdNqPwtxfL0OOHQpVHjC pmHJ49swtQ8ywjLVXgSur1fyLI1+idiTMiLzwisIusIPT/kxrxkmr3woi6iOku84B5 fxQdpOCbOMvEA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 40/47] mm/ksm: fix use of a freed anon_vma at swap-in To: =?utf-8?b?RGF2aWQgSGlsZGVuYnJhbmQgKEFybSk=?= , "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" , =?utf-8?b?TWF0dGhldyBXaWxjb3ggKE9yYWNsZSk=?= , "Jan Kara" , "Zi Yan" , "Lance Yang" , "Rik van Riel" , "Harry Yoo" , "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" Cc: kexec@lists.infradead.org, "Chris Mason" In-Reply-To: <20261029-fixes_core-v2-40-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-40-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:42:20 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 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 X-Archived-By: > A folio read from a swap slot previously shared by KSM can remain in the > swap cache after the process that first mapped it exits. Its anon_vma > can then be freed, so ksm_might_need_to_copy() must not dereference it > to compare roots. >=20 > Doing so can result in some false-positives, resulting in the reverse > mapping missing the new folio mapping, preventing migration and reclaim. >=20 > SLAB_TYPESAFE_BY_RCU allows individual anon_vma objects to be reused > immediately after freeing. A stale pointer can then refer to another > anon_vma whose root matches, even though the target VMA is not linked > to that anon_vma. >=20 > Move the anonymous rmap compatibility checks into > folio_anon_rmap_compatible(). Keep the page-index check and compare the > [ ... ] > Fixes: ba6f0ff3981e ("ksm: fix ksm swapin time optimization") > Cc: stable@vger.kernel.org > Reported-by: Chris Mason > Reviewed-by: Lorenzo Stoakes (ARM) > Signed-off-by: David Hildenbrand (Arm) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261029-fixes_core= -v2-0-a64ce7f83abb@kernel.org?part=3D40