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From: Xiang Mei <xmei5@asu.edu>
To: Dave Hansen <dave.hansen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>, Kees Cook <kees@kernel.org>,
	 Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@kernel.org>,
	 Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	 Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org,  linux-hardening@vger.kernel.org,
	Uladzislau Rezki <urezki@gmail.com>,
	 "Gustavo A . R . Silva" <gustavoars@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	 Jennifer Miller <jmill@asu.edu>, Tiffany Bao <tbao@asu.edu>,
	Ruoyu Wang <fishw@asu.edu>,  Adam Doupe <doupe@asu.edu>,
	Kyle Zeng <zengyhkyle@asu.edu>,
	Yan Shoshitaishvili <yans@asu.edu>
Subject: Re: [PATCH v2] mm/vmalloc: widen guard region to defeat ENTER-based stack pivot
Date: Tue, 30 Jun 2026 16:48:26 -0700	[thread overview]
Message-ID: <CAPpSM+Qf-=cG1yw7vpTexh5F6+J+c18m-xGjR7H+GJV6fdx_kg@mail.gmail.com> (raw)
In-Reply-To: <9ac1d214-aa8a-42e5-8903-15f8eac5cddd@intel.com>

On Tue, Jun 30, 2026 at 4:40 PM Dave Hansen <dave.hansen@intel.com> wrote:
>
> On 6/30/26 15:47, Xiang Mei wrote:
> > On Tue, Jun 30, 2026 at 3:14 PM H. Peter Anvin <hpa@zytor.com> wrote:
> >> 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.
> >>
> > You are right; CET breaks the assumption that this technique needs a
> > CFH primitive.
>
> I'm not sure what you're saying.
>
> Are you saying that this ENTER-based technique is worthless if IBT is in
> play, so the new stack gap is a worthless mitigation too?

IBT makes it hard to use a CFH primitive(including ENTER gadgets,
which are a subset of CFH gadgets).
Currently, it's worthless to enlarge the guard area for Fine-IBT/kCFI
protected targets.

Xiang

  reply	other threads:[~2026-06-30 23:48 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-29 21:47 Xiang Mei
2026-06-29 22:29 ` Dave Hansen
2026-06-29 23:28   ` Xiang Mei
2026-06-29 23:37     ` Dave Hansen
2026-06-30  1:22       ` Xiang Mei
2026-06-30 14:01         ` Dave Hansen
2026-06-30 14:58           ` Pedro Falcato
2026-07-01  7:23             ` Peter Zijlstra
2026-06-30 22:02           ` Xiang Mei
2026-06-30 22:05             ` Dave Hansen
2026-06-30 22:13               ` H. Peter Anvin
2026-06-30 22:47                 ` Xiang Mei
2026-06-30 23:40                   ` Dave Hansen
2026-06-30 23:48                     ` Xiang Mei [this message]
2026-07-01  7:19           ` Peter Zijlstra
2026-06-30 14:40     ` Pedro Falcato
2026-06-30 15:15       ` Dave Hansen
2026-06-30 21:54         ` Dave Hansen
2026-06-30 21:41       ` Xiang Mei
2026-07-01  7:27   ` Peter Zijlstra
2026-07-01  7:48     ` Peter Zijlstra
2026-07-01  7:58       ` H. Peter Anvin
2026-07-01  8:31         ` Peter Zijlstra
2026-07-01 21:04           ` Xiang Mei
2026-07-10 18:58             ` Dave Hansen

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