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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 1A463ECE561 for ; Mon, 24 Sep 2018 11:43:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D139D21486 for ; Mon, 24 Sep 2018 11:43:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D139D21486 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729704AbeIXRoq (ORCPT ); Mon, 24 Sep 2018 13:44:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51136 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728947AbeIXRoe (ORCPT ); Mon, 24 Sep 2018 13:44:34 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id A09B71070; Mon, 24 Sep 2018 11:42:53 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dr Silvio Cesare of InfoSect , Ronnie Sahlberg , Aurelien Aptel , Dan Carpenter , Steve French Subject: [PATCH 3.18 092/105] cifs: prevent integer overflow in nxt_dir_entry() Date: Mon, 24 Sep 2018 13:34:18 +0200 Message-Id: <20180924113122.044080444@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180924113113.268650190@linuxfoundation.org> References: <20180924113113.268650190@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit 8ad8aa353524d89fa2e09522f3078166ff78ec42 upstream. The "old_entry + le32_to_cpu(pDirInfo->NextEntryOffset)" can wrap around so I have added a check for integer overflow. Reported-by: Dr Silvio Cesare of InfoSect Reviewed-by: Ronnie Sahlberg Reviewed-by: Aurelien Aptel Signed-off-by: Dan Carpenter Signed-off-by: Steve French CC: Stable Signed-off-by: Greg Kroah-Hartman --- fs/cifs/readdir.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/fs/cifs/readdir.c +++ b/fs/cifs/readdir.c @@ -366,8 +366,15 @@ static char *nxt_dir_entry(char *old_ent new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) + pfData->FileNameLength; - } else - new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset); + } else { + u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset); + + if (old_entry + next_offset < old_entry) { + cifs_dbg(VFS, "invalid offset %u\n", next_offset); + return NULL; + } + new_entry = old_entry + next_offset; + } cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry); /* validate that new_entry is not past end of SMB */ if (new_entry >= end_of_smb) {