From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38CF52236F7; Wed, 22 Jul 2026 13:08:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784725735; cv=none; b=r4zYQ8geyeDe4y9nN46ubVGVUBOSBQszXTIvgxsqKUtQr9/FooptJfr5NgcamL+Vn2zXkOYPHuuDwpZGRM26psHUuyBgzxwFn3qqWmkJv6YVTmbi/HZpxU52IoaCeu/iEIJU6lEggTv7BSrACbFv1cJPYe2hrL51+SQ0a24vffw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784725735; c=relaxed/simple; bh=3gSD1hOZU42lj52sk+8oIlGlwBvURDsKRZs3kZoclWU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F/9neYQmyWRklAeyZw1bxx7HBgd1wgHBFutuA8TIuz8aRreALo5GUS4+dIAImnifu7QSZrzqSUkw9p2PPmx0W83BbCZZjX1l1W6jiFUh0GMkWo1m9B1mNIBETWqd9JVMETKozSBpmfnT7Els1xlYi/qIPmF338pbdHnUk3vSpWk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Aj9osxRS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Aj9osxRS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58D971F000E9; Wed, 22 Jul 2026 13:08:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784725733; bh=H+Qi617eo3zUgYds5z521wJuB64qpF7zXKkxOz66ms4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Aj9osxRSzFsqEtzDC0cumxQAnvyoe0mj6gU20GeYVJ8C3EFfEnr6Yqbs47vJU7fzW /v0RbK4gPBnGxJUW11IIkI9nFijKT4+ilYhQi8jK22XOk8OlTGr9XPLiF0F49yM8kO 1r7rb0K2YYL+sDdCOq6z1V6MxO6DVjtRfHm6Gaw4= Date: Wed, 22 Jul 2026 15:08:44 +0200 From: Greg KH To: James Bottomley Cc: sashiko-reviews@lists.linux.dev, Chris Mason , Roman Gushchin , linux-scsi@vger.kernel.org, ksummit@lists.linux.dev Subject: Re: How to fix problems with the sashiko review model Message-ID: <2026072224-moisture-gonad-409f@gregkh> References: <20260722041257.1557-1-pengpeng@iscas.ac.cn> <20260722042744.5C1B01F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 22, 2026 at 07:58:48AM -0400, James Bottomley wrote: > There doesn't seem to be a Sashiko list, so I added ksummit as the most > likely one to catch attention. We got this review in SCSI on this > thread: > > https://lore.kernel.org/linux-scsi/20260722041257.1557-1-pengpeng@iscas.ac.cn/ > > But this part of the review > > On Wed, 2026-07-22 at 04:27 +0000, sashiko-bot@kernel.org wrote: > [...] > > > + > > > + reply_len = mpi_reply->MsgLength * 4; > > > + if (reply_len < event_offset || reply_len > ioc->reply_sz) > > > + return false; > > > + > > > + event_data_len = le16_to_cpu(mpi_reply->EventDataLength) * > > > 4; > > > > [Severity: High] > > Is there a Time-of-Check to Time-of-Use window here since mpi_reply > > is read directly from shared DMA memory? > > > > The validation function reads bounds from mpi_reply, but after > > validation passes, mpt3sas_scsih_event_callback() re-reads fields > > like EventDataLength and NumEntries directly from the same DMA-backed > > memory. > > > > Could a malicious device mutate these fields in the window between > > validation and use to bypass the checks introduced by this patch? > > Is wrong. Hardware may never be presumed to be malicious (well, except > if it's virtual hardware provided by an untrusted host to a > confidential guest, but that's a very small list of drivers or it's a > USB or thunderbolt device designed to attack or exfiltrate data from an > unattended system). It may be buggy, but we never presume bugs until > someone finds a device exhibiting the bug in the field (so we don't > proactively fix them). > > The bigger part of this is that I was looking into how to fix this > (which might interest a broader swathe of developers than just SCSI). > I think the fault is in the review prompts: > > https://github.com/masoncl/review-prompts > > And what I need to do is to add an additional drivers.md file to > kernel/subsystems explaining this? If that's right I can send a pull > request, but I thought I'd check here because the audience is much > bigger than if it were to get discussed in the github PR. Please make this per-subsystem, as your description above doesn't hold for all types of devices or busses. See this thread where I describe what we do for USB and asking for much the same type of description for the virtio drivers: https://lore.kernel.org/all/2026072036-outburst-rebel-c71b@gregkh/ thanks, greg k-h