From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752161AbcBMAbw (ORCPT ); Fri, 12 Feb 2016 19:31:52 -0500 Received: from mail-ob0-f171.google.com ([209.85.214.171]:34693 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751965AbcBMAbu (ORCPT ); Fri, 12 Feb 2016 19:31:50 -0500 Date: Fri, 12 Feb 2016 17:31:47 -0700 From: David Brown To: Ard Biesheuvel Cc: kernel-hardening@lists.openwall.com, Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Kees Cook Subject: Re: [kernel-hardening] [PATCH] arm64: vdso: Mark vDSO code as read-only Message-ID: <20160213003147.GA12074@davidb.org> References: <1455141142-6838-1-git-send-email-david.brown@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 11, 2016 at 03:19:20PM +0100, Ard Biesheuvel wrote: >> diff --git a/arch/arm64/kernel/vdso/vdso.S b/arch/arm64/kernel/vdso/vdso.S >> index 60c1db5..db7c0f2 100644 >> --- a/arch/arm64/kernel/vdso/vdso.S >> +++ b/arch/arm64/kernel/vdso/vdso.S >> @@ -24,6 +24,7 @@ >> __PAGE_ALIGNED_DATA > >^^ You can get rid of this now as well Can we? The page is getting mapped to userspace, and if we didn't page align it, we could leak kernel read-only data to every userspace process. David From mboxrd@z Thu Jan 1 00:00:00 1970 From: david.brown@linaro.org (David Brown) Date: Fri, 12 Feb 2016 17:31:47 -0700 Subject: [kernel-hardening] [PATCH] arm64: vdso: Mark vDSO code as read-only In-Reply-To: References: <1455141142-6838-1-git-send-email-david.brown@linaro.org> Message-ID: <20160213003147.GA12074@davidb.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Feb 11, 2016 at 03:19:20PM +0100, Ard Biesheuvel wrote: >> diff --git a/arch/arm64/kernel/vdso/vdso.S b/arch/arm64/kernel/vdso/vdso.S >> index 60c1db5..db7c0f2 100644 >> --- a/arch/arm64/kernel/vdso/vdso.S >> +++ b/arch/arm64/kernel/vdso/vdso.S >> @@ -24,6 +24,7 @@ >> __PAGE_ALIGNED_DATA > >^^ You can get rid of this now as well Can we? The page is getting mapped to userspace, and if we didn't page align it, we could leak kernel read-only data to every userspace process. David From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com Date: Fri, 12 Feb 2016 17:31:47 -0700 From: David Brown Message-ID: <20160213003147.GA12074@davidb.org> References: <1455141142-6838-1-git-send-email-david.brown@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: Subject: Re: [kernel-hardening] [PATCH] arm64: vdso: Mark vDSO code as read-only To: Ard Biesheuvel Cc: kernel-hardening@lists.openwall.com, Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Kees Cook List-ID: On Thu, Feb 11, 2016 at 03:19:20PM +0100, Ard Biesheuvel wrote: >> diff --git a/arch/arm64/kernel/vdso/vdso.S b/arch/arm64/kernel/vdso/vdso.S >> index 60c1db5..db7c0f2 100644 >> --- a/arch/arm64/kernel/vdso/vdso.S >> +++ b/arch/arm64/kernel/vdso/vdso.S >> @@ -24,6 +24,7 @@ >> __PAGE_ALIGNED_DATA > >^^ You can get rid of this now as well Can we? The page is getting mapped to userspace, and if we didn't page align it, we could leak kernel read-only data to every userspace process. David