From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35520 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753877AbcHRN21 (ORCPT ); Thu, 18 Aug 2016 09:28:27 -0400 Subject: Patch "module: Invalidate signatures on force-loaded modules" has been added to the 4.4-stable tree To: ben@decadent.org.uk, gregkh@linuxfoundation.org, rusty@rustcorp.com.au Cc: , From: Date: Thu, 18 Aug 2016 15:28:32 +0200 Message-ID: <147152691215786@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 module: Invalidate signatures on force-loaded modules to the 4.4-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: module-invalidate-signatures-on-force-loaded-modules.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From bca014caaa6130e57f69b5bf527967aa8ee70fdd Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Thu, 28 Apr 2016 09:24:01 +0930 Subject: module: Invalidate signatures on force-loaded modules From: Ben Hutchings commit bca014caaa6130e57f69b5bf527967aa8ee70fdd upstream. Signing a module should only make it trusted by the specific kernel it was built for, not anything else. Loading a signed module meant for a kernel with a different ABI could have interesting effects. Therefore, treat all signatures as invalid when a module is force-loaded. Signed-off-by: Ben Hutchings Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- kernel/module.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/kernel/module.c +++ b/kernel/module.c @@ -2606,13 +2606,18 @@ static inline void kmemleak_load_module( #endif #ifdef CONFIG_MODULE_SIG -static int module_sig_check(struct load_info *info) +static int module_sig_check(struct load_info *info, int flags) { int err = -ENOKEY; const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; const void *mod = info->hdr; - if (info->len > markerlen && + /* + * Require flags == 0, as a module with version information + * removed is no longer the module that was signed + */ + if (flags == 0 && + info->len > markerlen && memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { /* We truncate the module to discard the signature */ info->len -= markerlen; @@ -2631,7 +2636,7 @@ static int module_sig_check(struct load_ return err; } #else /* !CONFIG_MODULE_SIG */ -static int module_sig_check(struct load_info *info) +static int module_sig_check(struct load_info *info, int flags) { return 0; } @@ -3444,7 +3449,7 @@ static int load_module(struct load_info long err; char *after_dashes; - err = module_sig_check(info); + err = module_sig_check(info, flags); if (err) goto free_copy; Patches currently in stable-queue which might be from ben@decadent.org.uk are queue-4.4/module-invalidate-signatures-on-force-loaded-modules.patch queue-4.4/documentation-module-signing.txt-note-need-for-version-info-if-reusing-a-key.patch