From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35530 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753797AbcHRN2v (ORCPT ); Thu, 18 Aug 2016 09:28:51 -0400 Subject: Patch "Documentation/module-signing.txt: Note need for version info if reusing a key" has been added to the 4.7-stable tree To: ben@decadent.org.uk, gregkh@linuxfoundation.org, rusty@rustcorp.com.au Cc: , From: Date: Thu, 18 Aug 2016 15:28:56 +0200 Message-ID: <147152693620799@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled Documentation/module-signing.txt: Note need for version info if reusing a key to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: documentation-module-signing.txt-note-need-for-version-info-if-reusing-a-key.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From b8612e517c3c9809e1200b72c474dbfd969e5a83 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 28 Apr 2016 09:24:05 +0930 Subject: Documentation/module-signing.txt: Note need for version info if reusing a key From: Ben Hutchings commit b8612e517c3c9809e1200b72c474dbfd969e5a83 upstream. Signing a module should only make it trusted by the specific kernel it was built for, not anything else. If a module signing key is used for multiple ABI-incompatible kernels, the modules need to include enough version information to distinguish them. Signed-off-by: Ben Hutchings Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- Documentation/module-signing.txt | 6 ++++++ 1 file changed, 6 insertions(+) --- a/Documentation/module-signing.txt +++ b/Documentation/module-signing.txt @@ -271,3 +271,9 @@ Since the private key is used to sign mo the private key to sign modules and compromise the operating system. The private key must be either destroyed or moved to a secure location and not kept in the root node of the kernel source tree. + +If you use the same private key to sign modules for multiple kernel +configurations, you must ensure that the module version information is +sufficient to prevent loading a module into a different kernel. Either +set CONFIG_MODVERSIONS=y or ensure that each configuration has a different +kernel release string by changing EXTRAVERSION or CONFIG_LOCALVERSION. Patches currently in stable-queue which might be from ben@decadent.org.uk are queue-4.7/module-invalidate-signatures-on-force-loaded-modules.patch queue-4.7/documentation-module-signing.txt-note-need-for-version-info-if-reusing-a-key.patch