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=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, 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 42880C04AAB for ; Mon, 6 May 2019 15:25:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20B7B205ED for ; Mon, 6 May 2019 15:25:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726947AbfEFPZj (ORCPT ); Mon, 6 May 2019 11:25:39 -0400 Received: from mx1.chost.de ([5.175.28.52]:40320 "EHLO mx1.chost.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726414AbfEFPZi (ORCPT ); Mon, 6 May 2019 11:25:38 -0400 X-Greylist: delayed 307 seconds by postgrey-1.27 at vger.kernel.org; Mon, 06 May 2019 11:25:37 EDT Received: from vm002.chost.de ([::ffff:192.168.122.102]) by mx1.chost.de with SMTP; Mon, 06 May 2019 17:21:16 +0200 id 000000000133BD2A.000000005CD050EC.00007663 Received: by vm002.chost.de (sSMTP sendmail emulation); Mon, 06 May 2019 17:21:15 +0200 From: Christoph Probst To: linux-cifs@vger.kernel.org Cc: Steve French , samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, Christoph Probst Subject: [PATCH] cifs: fix strcat buffer overflow in smb21_set_oplock_level() Date: Mon, 6 May 2019 17:16:32 +0200 Message-Id: <1557155792-2703-1-git-send-email-kernel@probst.it> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Change strcat to strcpy in the "None" case as it is never valid to append "None" to any other message. It may also overflow char message[5], in a race condition on cinode if cinode->oplock is unset by another thread after "RHW" or "RH" had been written to message. Signed-off-by: Christoph Probst --- fs/cifs/smb2ops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c36ff0d..5fd5567 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2936,7 +2936,7 @@ smb21_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock, strcat(message, "W"); } if (!cinode->oplock) - strcat(message, "None"); + strcpy(message, "None"); cifs_dbg(FYI, "%s Lease granted on inode %p\n", message, &cinode->vfs_inode); } -- 2.1.4