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_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 7B9CCC43387 for ; Tue, 15 Jan 2019 16:53:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B31C20645 for ; Tue, 15 Jan 2019 16:53:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547571187; bh=5ncq41RYGvHr9PvVIHoGKoKImc2WcR6TlPwNKqVhmVA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lIJm4LjQhkjqPZENgstCh0skgkG9Q58xMmK0OpPIaFAryz6cnJr29W4W2mBu2r/8N rjy8zodwiVo7snfUyAQ5ilu7rCrehfM5I1Bec076B8vVwU00DcjrIjhYUQq+0FUzh5 Hnq0NaoCc9oykMberpCDPZvcb1miL17UjB7Q81lg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732143AbfAOQxG (ORCPT ); Tue, 15 Jan 2019 11:53:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:33448 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387417AbfAOQnz (ORCPT ); Tue, 15 Jan 2019 11:43:55 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 4A6F72054F; Tue, 15 Jan 2019 16:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547570634; bh=5ncq41RYGvHr9PvVIHoGKoKImc2WcR6TlPwNKqVhmVA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1AylTMYHPfZAqWUOO0z/aM7tbiNqo+L4z1FE9eWyjSqWUJq1sOxpH2gSU4oRJhdng VEXQ9HkyTwBjljU3c1L8mYiFxLEoi+N5MqIhRg2vtt1nF/4r4NZUDgwcCVm4uMCqnc 81GDC5SmnHcZVSIVEsut1XE5RlQfmMJUZxGfYYhQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ross Lagerwall , Steve French Subject: [PATCH 4.20 16/57] cifs: Fix potential OOB access of lock element array Date: Tue, 15 Jan 2019 17:35:57 +0100 Message-Id: <20190115154911.634403832@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190115154910.734892368@linuxfoundation.org> References: <20190115154910.734892368@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ross Lagerwall commit b9a74cde94957d82003fb9f7ab4777938ca851cd upstream. If maxBuf is small but non-zero, it could result in a zero sized lock element array which we would then try and access OOB. Signed-off-by: Ross Lagerwall Signed-off-by: Steve French CC: Stable Signed-off-by: Greg Kroah-Hartman --- fs/cifs/file.c | 8 ++++---- fs/cifs/smb2file.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1131,10 +1131,10 @@ cifs_push_mandatory_locks(struct cifsFil /* * Accessing maxBuf is racy with cifs_reconnect - need to store value - * and check it for zero before using. + * and check it before using. */ max_buf = tcon->ses->server->maxBuf; - if (!max_buf) { + if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) { free_xid(xid); return -EINVAL; } @@ -1471,10 +1471,10 @@ cifs_unlock_range(struct cifsFileInfo *c /* * Accessing maxBuf is racy with cifs_reconnect - need to store value - * and check it for zero before using. + * and check it before using. */ max_buf = tcon->ses->server->maxBuf; - if (!max_buf) + if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) return -EINVAL; max_num = (max_buf - sizeof(struct smb_hdr)) / --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -122,10 +122,10 @@ smb2_unlock_range(struct cifsFileInfo *c /* * Accessing maxBuf is racy with cifs_reconnect - need to store value - * and check it for zero before using. + * and check it before using. */ max_buf = tcon->ses->server->maxBuf; - if (!max_buf) + if (max_buf < sizeof(struct smb2_lock_element)) return -EINVAL; max_num = max_buf / sizeof(struct smb2_lock_element);