From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 991EC2C237E; Tue, 30 Jun 2026 22:30:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782858633; cv=none; b=o5r6ZrFjq2fzMQeW72LOeLZd8DFF9tbDMtOInmcwIRIwDBJ6yngw+nOrQfEYPNzlWzyhj/EcbS9DVPKRgfb4ygJghgYjLfY2xUzvUFfT13Gn4K84sVku9V7GG32Vm+adrI45rCuWsILaHdL4WuzPk0079C/4dRYa5kYTZHM+D1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782858633; c=relaxed/simple; bh=/KpcX1aZjAvLJR2Xr2cKCzso/oBzdylfniMZK8fXSmM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=T85n/VY0pQZoC35P1Zq3e1Hx98R9tO5EBHBFtEtvAsjtZpCH5/nOQdgvYXeldYh8J3BgvJ3eXNq4VcLOl7Zc4nfvIk8aXOTrUHp0cs3B+GUuI0D7Hl99kt7RJSj758ANYIAq2k43/uCm8QUPY1WGBrsm3iMSQA8sjCO2OO3TMVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=Le3gGuua; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="Le3gGuua" Received: from [10.124.221.63] ([192.55.55.46]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 65UME0h43868545 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Tue, 30 Jun 2026 15:14:07 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 65UME0h43868545 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026062701; t=1782857649; bh=WRAReKFHVDRGS4isJ32YVCLo/+68kLt6VkxwNq2bQEI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Le3gGuua4QujchktITkW78RVVX/pciaMDX+V4ewXrvem4cEKDcRHD8/vnw23DlKfa T2dLkYtbU5PineWlU6if8Hq4SFVNjwap+LKMcAVXKfIqPRc+bupAm6MVrxKbTG5Q/s +50YCU+/ZHCfZNHdQGj/lJIAcVpAfNuAhRtElFwAthYOvbWicz45cYE3/cnNbvh902 XWG2CLsXwBwoabcJ1tqfI4v7xH8EkG02J66Y7yuvA26XfXfCoiHIzF7fJOwgynL2BO fmECy8fAjZ25wurQs8oPrysAOu+xPCYiZUWNDiicky2BP2jl/rd1rQAAHJew1wB5J5 9D9VJBSMWpVew== Message-ID: <86e805c9-ede0-473c-b8a4-8b20439eaa6b@zytor.com> Date: Tue, 30 Jun 2026 15:13:55 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/vmalloc: widen guard region to defeat ENTER-based stack pivot To: Dave Hansen , Xiang Mei Cc: Kees Cook , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, linux-hardening@vger.kernel.org, Uladzislau Rezki , "Gustavo A . R . Silva" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jennifer Miller , Tiffany Bao , Ruoyu Wang , Adam Doupe , Kyle Zeng , Yan Shoshitaishvili References: <20260629214712.1198680-1-xmei5@asu.edu> <4e96acf4-25e7-4f30-8455-f9b3f49062be@intel.com> Content-Language: en-US, sv-SE From: "H. Peter Anvin" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2026-06-30 15:05, Dave Hansen wrote: > On 6/30/26 15:02, Xiang Mei wrote: >> Please feel free to ask any questions; I am glad to help. > > How do the CET features: kernel IBT and the (theoretical for Linux) > kernel shadow stacks impact the situation? CET should prevent this from being the target of a JOP attack. Kernel shadow stacks should prevent most stack-pivot attacks in general. -hpa