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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDF4CECE58E for ; Thu, 10 Oct 2019 08:49:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88D0B21BE5 for ; Thu, 10 Oct 2019 08:49:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697350; bh=t8FOo74chH5+mY1vjZfg1kh1OIOjZTnn/JRdo0W3LEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IvKE4itEsHGRmweRyY9PJ9eMHWCRy95sRTmcO3AudhR0RPJF0gDtsNPcE1y+Og4Um h88i90egQjy9IT/4I82hLecqQdRHLQ5h8whaKas0Tb/X8Hi3iQpxeYT3tSmggw55ok 2xobBbVhSPJ1DYQlOV3pBxakC40mc2zAnKPHJHVE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389767AbfJJItJ (ORCPT ); Thu, 10 Oct 2019 04:49:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:55522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388936AbfJJItG (ORCPT ); Thu, 10 Oct 2019 04:49:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5DC69218AC; Thu, 10 Oct 2019 08:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697345; bh=t8FOo74chH5+mY1vjZfg1kh1OIOjZTnn/JRdo0W3LEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WbQH2RdlYdRF792jVzVA8Ys5j2vD67ORIX3jOckU/X7KZV9JgUvdzzbT3mWhY91mt 4BJ48O7VTIpzCJVz5XFs9jfcLm6ljmHAgmHM0UAlV53h/7DaLshESoQLXH06Znfe0v V1gyF7Yi//VwVzgz3N+ju3oFKYGDIxiRa5xKpaV4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Richard Weinberger , Chao Yu , Gao Xiang Subject: [PATCH 4.19 108/114] staging: erofs: fix an error handling in erofs_readdir() Date: Thu, 10 Oct 2019 10:36:55 +0200 Message-Id: <20191010083613.962255734@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Gao Xiang commit acb383f1dcb4f1e79b66d4be3a0b6f519a957b0d upstream. Richard observed a forever loop of erofs_read_raw_page() [1] which can be generated by forcely setting ->u.i_blkaddr to 0xdeadbeef (as my understanding block layer can handle access beyond end of device correctly). After digging into that, it seems the problem is highly related with directories and then I found the root cause is an improper error handling in erofs_readdir(). Let's fix it now. [1] https://lore.kernel.org/r/1163995781.68824.1566084358245.JavaMail.zimbra@nod.at/ Reported-by: Richard Weinberger Fixes: 3aa8ec716e52 ("staging: erofs: add directory operations") Cc: # 4.19+ Reviewed-by: Chao Yu Signed-off-by: Gao Xiang Link: https://lore.kernel.org/r/20190818125457.25906-1-hsiangkao@aol.com [ Gao Xiang: Since earlier kernels don't define EFSCORRUPTED, let's use original error code instead. ] Signed-off-by: Gao Xiang Signed-off-by: Greg Kroah-Hartman --- drivers/staging/erofs/dir.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/drivers/staging/erofs/dir.c +++ b/drivers/staging/erofs/dir.c @@ -100,8 +100,15 @@ static int erofs_readdir(struct file *f, unsigned nameoff, maxsize; dentry_page = read_mapping_page(mapping, i, NULL); - if (IS_ERR(dentry_page)) - continue; + if (dentry_page == ERR_PTR(-ENOMEM)) { + err = -ENOMEM; + break; + } else if (IS_ERR(dentry_page)) { + errln("fail to readdir of logical block %u of nid %llu", + i, EROFS_V(dir)->nid); + err = PTR_ERR(dentry_page); + break; + } lock_page(dentry_page); de = (struct erofs_dirent *)kmap(dentry_page);