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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 0B379C04AB6 for ; Tue, 28 May 2019 07:05:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C95202075B for ; Tue, 28 May 2019 07:05:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sTVCTQwc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbfE1HFb (ORCPT ); Tue, 28 May 2019 03:05:31 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:42005 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbfE1HFa (ORCPT ); Tue, 28 May 2019 03:05:30 -0400 Received: by mail-pf1-f196.google.com with SMTP id r22so8003798pfh.9; Tue, 28 May 2019 00:05:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=E/ZAaCWtOroQWVvLC5q9wuH/qlBcoxb4vLQTQm3UQbo=; b=sTVCTQwcjOUbBeDTPZ9slIgPL7vc7+8M/O2YOnWqEz0DAzf2tUwdnTlU0GzopMLZJq mG8Nq01ounojAaiDTcwXpLoOCOfxfzprjI3G7jL2No2j89M8v51FdKkrH6eimAPl6ifx Ki3tWybo3KPGSaRLa/U+9d+PeIEdjH5EFMtzJlYcCnLR1sCkNUix7HMiWGK/c3Riidzj eVak/YJO22tACt/XU1quCIZ1d3CurojyziZydPbyttk0mk6zjFWroMJ2MY30Ys3OUA5a G8pzUEHYUXNswLQ74XLHjMj2bKfvgVcCzJ+YzapQqtnEUa6HwC1mxJXaW9T/5BUxw1RE gA0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=E/ZAaCWtOroQWVvLC5q9wuH/qlBcoxb4vLQTQm3UQbo=; b=EFPv7I6iQ8EfxafSkJ9a9A+QY27AReyG0DSSsBLvN+45WeSDDHHElOlA9Z1V/DXiu8 4rW/KUJyFnz7JUPSFOzsWbq5dwaA0zRDzvci10b6iOX8LGN4Gx6nwjICzVp1k2HRsTTN Omn254Wka3k4jvuJLjrV7ggfJ6R3v4iZHpND53S41KBvlnXUP3clERsMRrDk2TGnK9P5 fcRE91mX9WouiooI5g1t8BkxjAk8o9V0VLDgyBHtfJLdlGLYW0+5wCZAIvt1zXgomMgn VomFCGzsyl1CLyMskI+zKmsMOV11X5pl7+Z5Nr1ozg31eQVL9LNuXAnKCov8OQdMQkg1 CJxg== X-Gm-Message-State: APjAAAU92PQ15Ron68dPNYSRAN5+LR57NyjJYf8bumiu8pIsThbJeLNr ny9PlV8skY438c8Jj4qtHAQ= X-Google-Smtp-Source: APXvYqwjuycOJymYacAnddrW34eMUmkeWw3rETyOEQpBXYDURHWelTLHkKdBzzVDLXiSgtPyJdGQhw== X-Received: by 2002:a63:ec02:: with SMTP id j2mr107551727pgh.340.1559027129956; Tue, 28 May 2019 00:05:29 -0700 (PDT) Received: from zhanggen-UX430UQ ([66.42.35.75]) by smtp.gmail.com with ESMTPSA id d15sm33527932pfm.186.2019.05.28.00.05.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 May 2019 00:05:29 -0700 (PDT) Date: Tue, 28 May 2019 15:05:08 +0800 From: Gen Zhang To: Suganath Prabu Subramani Cc: "Martin K. Petersen" , Sathya Prakash , "James E.J. Bottomley" , PDL-MPT-FUSIONLINUX , linux-scsi , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mpt3sas_ctl: fix double-fetch bug in _ctl_ioctl_main() Message-ID: <20190528070508.GA18498@zhanggen-UX430UQ> References: <20190527005716.GA17015@zhanggen-UX430UQ> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 28, 2019 at 11:44:35AM +0530, Suganath Prabu Subramani wrote: > Please consider this patch as Ack-by: Suganath Prabu S > > > Thanks, > Suganath. > > > On Mon, May 27, 2019 at 6:27 AM Gen Zhang wrote: > > > > In _ctl_ioctl_main(), 'ioctl_header' is fetched the first time from > > userspace. 'ioctl_header.ioc_number' is then checked. The legal result > > is saved to 'ioc'. Then, in condition MPT3COMMAND, the whole struct is > > fetched again from the userspace. Then _ctl_do_mpt_command() is called, > > 'ioc' and 'karg' as inputs. > > > > However, a malicious user can change the 'ioc_number' between the two > > fetches, which will cause a potential security issues. Moreover, a > > malicious user can provide a valid 'ioc_number' to pass the check in > > first fetch, and then modify it in the second fetch. > > > > To fix this, we need to recheck the 'ioc_number' in the second fetch. > > > > Signed-off-by: Gen Zhang > > --- > > diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c > > index b2bb47c..5181c03 100644 > > --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c > > +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c > > @@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg, > > break; > > } > > > > + if (karg.hdr.ioc_number != ioctl_header.ioc_number) { > > + ret = -EINVAL; > > + break; > > + } > > if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) { > > uarg = arg; > > ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf); Thanks for your reply, Suganath. Thanks Gen