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From: Kees Cook <kees@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	alyssa.milburn@intel.com, scott.d.constable@intel.com,
	joao@overdrivepizza.com, andrew.cooper3@citrix.com,
	jpoimboe@kernel.org, jose.marchesi@oracle.com,
	hjl.tools@gmail.com, ndesaulniers@google.com,
	samitolvanen@google.com, nathan@kernel.org, ojeda@kernel.org,
	alexei.starovoitov@gmail.com, mhiramat@kernel.org, jmill@asu.edu
Subject: Re: [PATCH v3 07/10] x86/ibt: Add paranoid FineIBT mode
Date: Wed, 19 Feb 2025 10:05:56 -0800	[thread overview]
Message-ID: <202502191005.11B95F4CB8@keescook> (raw)
In-Reply-To: <20250219163515.040300905@infradead.org>

On Wed, Feb 19, 2025 at 05:21:14PM +0100, Peter Zijlstra wrote:
> Due to concerns about circumvention attacks against FineIBT on 'naked'
> ENDBR, add an additional caller side hash check to FineIBT. This
> should make it impossible to pivot over such a 'naked' ENDBR
> instruction at the cost of an additional load.
> 
> The specific pivot reported was against the SYSCALL entry site and
> FRED will have all those holes fixed up.
> 
> This specific fineibt_paranoid_start[] sequence was concocted by
> Scott.
> 
> Reported-by: Jennifer Miller <jmill@asu.edu>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

With patch 6's misplaced chunk moved, looks good:

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

  parent reply	other threads:[~2025-02-19 18:06 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-19 16:21 [PATCH v3 00/10] x86/ibt: FineIBT-BHI Peter Zijlstra
2025-02-19 16:21 ` [PATCH v3 01/10] x86/cfi: Add warn option Peter Zijlstra
2025-02-19 17:50   ` Kees Cook
2025-02-19 17:56     ` Peter Zijlstra
2025-02-19 16:21 ` [PATCH v3 02/10] x86/ibt: Add exact_endbr() helper Peter Zijlstra
2025-02-19 17:51   ` Kees Cook
2025-02-19 16:21 ` [PATCH v3 03/10] x86/traps: Decode 0xEA #UD Peter Zijlstra
2025-02-19 16:47   ` Andrew Cooper
2025-02-19 16:49     ` Peter Zijlstra
2025-02-19 17:52   ` Kees Cook
2025-02-19 16:21 ` [PATCH v3 04/10] x86/traps: Allow custom fixups in handle_bug() Peter Zijlstra
2025-02-19 17:55   ` Kees Cook
2025-02-19 18:17     ` Peter Zijlstra
2025-02-19 16:21 ` [PATCH v3 05/10] x86/ibt: Optimize FineIBT sequence Peter Zijlstra
2025-02-19 17:15   ` Andrew Cooper
2025-02-20 18:28     ` Constable, Scott D
2025-02-19 18:01   ` Kees Cook
2025-02-19 18:18     ` Peter Zijlstra
2025-02-19 18:23       ` Kees Cook
2025-02-19 16:21 ` [PATCH v3 06/10] x86/traps: Decode LOCK Jcc.d8 #UD Peter Zijlstra
2025-02-19 16:45   ` Peter Zijlstra
2025-02-19 18:20   ` Kees Cook
2025-02-19 18:33     ` Peter Zijlstra
2025-02-19 19:44       ` Peter Zijlstra
2025-02-19 16:21 ` [PATCH v3 07/10] x86/ibt: Add paranoid FineIBT mode Peter Zijlstra
2025-02-19 17:31   ` Andrew Cooper
2025-02-19 20:07     ` Peter Zijlstra
2025-02-21 13:40     ` David Laight
2025-02-19 18:05   ` Kees Cook [this message]
2025-02-19 16:21 ` [PATCH v3 08/10] x86: BHI stubs Peter Zijlstra
2025-02-19 18:07   ` Kees Cook
2025-02-19 18:07     ` Peter Zijlstra
2025-02-19 16:21 ` [PATCH v3 09/10] x86/ibt: Implement FineIBT-BHI mitigation Peter Zijlstra
2025-02-19 18:11   ` Kees Cook
2025-02-19 16:21 ` [PATCH v3 10/10] x86/ibt: Optimize fineibt-bhi arity 1 case Peter Zijlstra
2025-02-19 18:21   ` Kees Cook
2025-02-19 17:36 ` [PATCH v3 00/10] x86/ibt: FineIBT-BHI Kees Cook
2025-02-20 11:27 ` Peter Zijlstra

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