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 E27B7EB64DC for ; Mon, 26 Jun 2023 18:39:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232447AbjFZSjf (ORCPT ); Mon, 26 Jun 2023 14:39:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232444AbjFZSje (ORCPT ); Mon, 26 Jun 2023 14:39:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61C65ED for ; Mon, 26 Jun 2023 11:39:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA7F160F4F for ; Mon, 26 Jun 2023 18:39:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 001AEC433C8; Mon, 26 Jun 2023 18:39:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804772; bh=V1aeuxXObHP5fwAg9Nw3YSc27Jjs2aasKMFlzhkHOvI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0ggtLrvuSD8UeL+eACtIdlddeQXQCtjLR3pwBZTpe7LXUtmiOAWHdeGgrsDvKUAoZ 5i97ygAFPHVvFi+NLaVa/fENR4Ckz9tLsQzFtctNn6wKLOeFSMQeDSPxVlXArC5BDt klXckx8HVyxTIFiJ9SGYK7/83CsEUZwGpCK5t6rU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryusuke Konishi , syzbot+53369d11851d8f26735c@syzkaller.appspotmail.com, Andrew Morton Subject: [PATCH 5.15 35/96] nilfs2: prevent general protection fault in nilfs_clear_dirty_page() Date: Mon, 26 Jun 2023 20:11:50 +0200 Message-ID: <20230626180748.416529272@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180746.943455203@linuxfoundation.org> References: <20230626180746.943455203@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ryusuke Konishi commit 782e53d0c14420858dbf0f8f797973c150d3b6d7 upstream. In a syzbot stress test that deliberately causes file system errors on nilfs2 with a corrupted disk image, it has been reported that nilfs_clear_dirty_page() called from nilfs_clear_dirty_pages() can cause a general protection fault. In nilfs_clear_dirty_pages(), when looking up dirty pages from the page cache and calling nilfs_clear_dirty_page() for each dirty page/folio retrieved, the back reference from the argument page to "mapping" may have been changed to NULL (and possibly others). It is necessary to check this after locking the page/folio. So, fix this issue by not calling nilfs_clear_dirty_page() on a page/folio after locking it in nilfs_clear_dirty_pages() if the back reference "mapping" from the page/folio is different from the "mapping" that held the page/folio just before. Link: https://lkml.kernel.org/r/20230612021456.3682-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+53369d11851d8f26735c@syzkaller.appspotmail.com Closes: https://lkml.kernel.org/r/000000000000da4f6b05eb9bf593@google.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/nilfs2/page.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -369,7 +369,15 @@ void nilfs_clear_dirty_pages(struct addr struct page *page = pvec.pages[i]; lock_page(page); - nilfs_clear_dirty_page(page, silent); + + /* + * This page may have been removed from the address + * space by truncation or invalidation when the lock + * was acquired. Skip processing in that case. + */ + if (likely(page->mapping == mapping)) + nilfs_clear_dirty_page(page, silent); + unlock_page(page); } pagevec_release(&pvec);