From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 595AACE79D0 for ; Wed, 20 Sep 2023 12:00:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235119AbjITMAT (ORCPT ); Wed, 20 Sep 2023 08:00:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38008 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235095AbjITMAS (ORCPT ); Wed, 20 Sep 2023 08:00:18 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 754A3A3 for ; Wed, 20 Sep 2023 05:00:12 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C45E4C433C7; Wed, 20 Sep 2023 12:00:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695211212; bh=i5CwbQ9hFqvnMq7NRhr9raHAM4+J7JWAsw7+POd0pZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qa1kzFBx+M5yinArzb4o6XfyUc1vcHj+Rd7s6Cbm5ihsw6lWdWqiABu9+ITWtrkFl xeEyCzXupGuPkpmOcQtTqcneUupvjoG56TN3P6Oaal5B3D8MCzN0IU/ymnIQE6mpyC ATLubiI1jAxH97mSsG3cqt05nSAjtLBPiba0fkUM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com, Andrew Morton Subject: [PATCH 4.14 010/186] nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers() Date: Wed, 20 Sep 2023 13:28:33 +0200 Message-ID: <20230920112837.221545420@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112836.799946261@linuxfoundation.org> References: <20230920112836.799946261@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryusuke Konishi commit f83913f8c5b882a312e72b7669762f8a5c9385e4 upstream. A syzbot stress test reported that create_empty_buffers() called from nilfs_lookup_dirty_data_buffers() can cause a general protection fault. Analysis using its reproducer revealed that the back reference "mapping" from a page/folio has been changed to NULL after dirty page/folio gang lookup in nilfs_lookup_dirty_data_buffers(). Fix this issue by excluding pages/folios from being collected if, after acquiring a lock on each page/folio, its back reference "mapping" differs from the pointer to the address space struct that held the page/folio. Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Ryusuke Konishi Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/segment.c | 5 +++++ fs/nilfs2/segment.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -743,6 +743,11 @@ static size_t nilfs_lookup_dirty_data_bu break; lock_page(page); + if (unlikely(page->mapping != mapping)) { + /* Exclude pages removed from the address space */ + unlock_page(page); + continue; + } if (!page_has_buffers(page)) create_empty_buffers(page, i_blocksize(inode), 0); unlock_page(page);