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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5487DC77B7C for ; Sun, 7 May 2023 05:11:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229653AbjEGFLU (ORCPT ); Sun, 7 May 2023 01:11:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229527AbjEGFLS (ORCPT ); Sun, 7 May 2023 01:11:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68DED9EF1 for ; Sat, 6 May 2023 22:11:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EF38B61007 for ; Sun, 7 May 2023 05:11:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABD69C433EF; Sun, 7 May 2023 05:11:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683436275; bh=9dMvR61Umk33l8NiH/Y6Inl8qXkruhqzkWVUyT4NMoU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=U1rC+NEVrfu4MX+T1SHinnpu8dJN7BlKA6FFbH8V+rJc+0JSsdqZkYBi4v5McZG+z 4/LOpqpphgUdcrS+oAfqc03ZsnrhMOieU0O8ZcAgZcNz+54go8UPCrerXRRclMnM5/ LPeATUe2ns2Akf2eiqd1kb9x23l2Uo4vJZmqeF94= Date: Sun, 7 May 2023 07:11:11 +0200 From: Greg KH To: Ard Biesheuvel Cc: stable@vger.kernel.org Subject: Re: [PATCH 5.10.y 1/2] arm64: Always load shadow stack pointer directly from the task struct Message-ID: <2023050757-starless-tacking-d9f9@gregkh> References: <20230506123434.63470-1-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230506123434.63470-1-ardb@kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Sat, May 06, 2023 at 02:34:33PM +0200, Ard Biesheuvel wrote: > All occurrences of the scs_load macro load the value of the shadow call > stack pointer from the task which is current at that point. So instead > of taking a task struct register argument in the scs_load macro to > specify the task struct to load from, let's always reference the current > task directly. This should make it much harder to exploit any > instruction sequences reloading the shadow call stack pointer register > from memory. > > Signed-off-by: Ard Biesheuvel > Acked-by: Mark Rutland > Reviewed-by: Kees Cook > Link: https://lore.kernel.org/r/20230109174800.3286265-2-ardb@kernel.org > Signed-off-by: Catalin Marinas > Signed-off-by: Ard Biesheuvel > --- > arch/arm64/include/asm/scs.h | 7 ++++--- > arch/arm64/kernel/entry.S | 4 ++-- > arch/arm64/kernel/head.S | 2 +- > 3 files changed, 7 insertions(+), 6 deletions(-) What is the git commit id of this in Linus's tree? thanks, greg k-h