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 D8703606A31A for ; Fri, 30 Oct 2026 03:40:33 +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=HipNfAnx; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=G17BoS7g 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=XkRzF+WlqeaBLSpPzXLW1Jl6kgCZWyaasAg+pMaJLIQ=; b=HipNfAnxFFEZDOtsRZQtRYhQh8 L+8WV1xRdBLVA0XVr9txN5jN/2OhJKHwLazLe4/x8CVneVjkV2/xtvTMppJDEescpcuCxY5sJ3N4M z63/wkSuaUJt89rviB1VgZ35IiFZE5/MkUASgJHdvjvu1ixy8oFs4GfflaFAYYHxdeyuYHamG+EOG SqcxuaKSHE9nnFIa4gzP+qRtPSKrALSOKrtqbXvj7dUmSNLKRk6ITGUGDTbyc0Hl3JlGg//ikjD4a VR5J1ANVfUR2/xXxVB5poBNHpK6SbLcOLhrdUeNQ+DwOMRFJ2DmSqpreqttvu5IKIPEHzSKbs4RCj Q8svKNzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTl-0000000AjpO-2Kav; Fri, 30 Oct 2026 03:40:33 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTj-0000000AjnP-2iGP for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:40:31 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 9583B600C8; Fri, 30 Oct 2026 03:40:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD51E1F0093A; Fri, 30 Oct 2026 03:40:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331630; bh=XkRzF+WlqeaBLSpPzXLW1Jl6kgCZWyaasAg+pMaJLIQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=G17BoS7gfahcAXjf9xyqQiMpRmvqkzPXasXH1TYdhV8HqkcDy5VxevigH21GsjHnb Es3Vxp+F1zJdzrnhb+PoVuaoXFXHzDPYj5MldRXbxfcwDVb/b7Gvcy1EVN1TRPd0gy nU5yMbUxhILbx9Cz6Yhlb5n52jJHlwczxgZSLx02E9bAOkqHnK8cYJL2Ok6Qwx6sjp 7bI+vhbd6AgzGGdCARObLuci2dTPekqiX40VB8jMgKjIsJan7NLgg+eUV1MOUAsJYC 6Cl+OoLybaBzHkxftVptzD4LkyIvKjVtjKwFL2FC44cBw/FmTQuzMu3jM4n/pdPceo MVpM0K1man8ig== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 06/47] 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: <20261029-fixes_core-v2-6-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-6-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:40:27 +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: > 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 ] > Reviewed-by: Rik van Riel > 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=3D6