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 E8423606A31B for ; Tue, 27 Oct 2026 00:12:24 +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=kIB53WeB; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=k9IScvKf 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=gb/1bbxcMbIHteWU8oNZytTv52FHzyDRDEb/Cge1uPQ=; b=kIB53WeB7tybakJuga6+qXROrZ DtTOM2DEQmeYiyhDz80BuHLknTwopuhYv2Nofbwj/rsuixENTN6NBK4Nt1XhNtqyx7Sm6dYKmovTl avZI8XmgrBsMTJs6D7PiWOburkWjQPuCYbuZJzOkfDoDO85uA69dIS1OymRajQmMrKd5ggyNyEiFK bKvc4OUPuulFO3QK0zhNyJ1VcgyVgb3e2EfDPmEr4yV/ssECsOYrthTdP/rCt4GuZV7GFgx3RuzpN wPgsFhH6OJqtQDbDQq7QwDQP1kUtpvFGHqrgzY9VYw0dwT0d3kSQ+MoQ6/OtTou25zLZvxNGJTQkf etc8/mFw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUng-00000003UlG-2fCq; Tue, 27 Oct 2026 00:12:24 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLUnf-00000003Uk3-1kZS for kexec@lists.infradead.org; Tue, 27 Oct 2026 00:12:23 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 2254640A3E; Tue, 27 Oct 2026 00:12:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BAF01F01828; Tue, 27 Oct 2026 00:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793059943; bh=gb/1bbxcMbIHteWU8oNZytTv52FHzyDRDEb/Cge1uPQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=k9IScvKfAKljpKlN0EOWCqfU+DgWdAu9Gs6f8R44C+LAIZA+aNgu8aWbFEh7W9M6l 3Z17WcJZKY5jZWyHtiPomLfjjajgVb5FPkqD4ix2QGwoWipZ8Iv/0dkTcoDiM65vMr Hr/3tm6PpRx8ZufUyY+lc2DWReV+nSWY1BmEGVw7+eFR86ks0cOPbNOsUtV+F/MFMa hC8sILrjiLVA3ab0N1D6SRGo09NID7JWS+2uZBan5FurZyGL3FQZ/5w1IV7K97kNib 3lIeqxqqyM2QeHc60AxZ64JJAyFX/xpzEwuYdwriSkE+9/Ot5eZM2pwQ4s+4leFmcB 8D4MOGSbJOtnA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 06/46] mm/filemap: read mapping->a_ops->free_folio under i_lock 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, "Josef Bacik" In-Reply-To: <20261027-fixes_core-v1-6-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> <20261027-fixes_core-v1-6-6f74bec9a5bb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 00:12:19 +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=-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 X-Archived-By: > From: Josef Bacik >=20 > memory_failure() -> ... -> filemap_remove_folio() can read mapping->a_ops > after the inode has been freed. Once the folio is deleted from the > pagecache it no longer pins the mapping, so after i_lock is dropped > e.g., a concurrent final iput() can evict and free the inode before > filemap_free_folio() looks up mapping->a_ops->free_folio. >=20 > Most callers hold a reference on the inode, but not all. >=20 > Documentation/filesystems/vfs.rst explicitly states that ->free_folio() > must not assume the original address_space mapping still exists. >=20 > Fix it by loading ->free_folio while i_lock is still held, similar to > what folio_unmap_invalidate() does. >=20 > Inline filemap_free_folio() into its remaining caller such that > delete_from_page_cache_batch() also just loads the callback before > dropping the i_lock. >=20 > The bug was found by code inspection and has not been reproduced. >=20 > Fix generated by an LLM and sent by Josef Bacik in private. >=20 > Fixes: 59c66c5f8c4f ("mm: factor out page cache page freeing into a separ= ate function") > Cc: stable@vger.kernel.org > Signed-off-by: Josef Bacik > [ david: get rid of filemap_free_folio() entirely; improve patch descript= ion ] > 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/20261027-fixes_core= -v1-0-6f74bec9a5bb@kernel.org?part=3D6