Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753987AbaBZUMR (ORCPT ); Wed, 26 Feb 2014 15:12:17 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:44142 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753369AbaBZULo (ORCPT ); Wed, 26 Feb 2014 15:11:44 -0500 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: keescook@chromium.org, gregkh@linuxfoundation.org, hpa@zytor.com, linux-efi@vger.kernel.org, jmorris@namei.org, linux-security-module@vger.kernel.org, Matthew Garrett Subject: [PATCH 08/12] kexec: Disable at runtime if trusted_kernel is true Date: Wed, 26 Feb 2014 15:11:09 -0500 Message-Id: <1393445473-15068-9-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> References: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 209.6.207.143 X-SA-Exim-Mail-From: matthew.garrett@nebula.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kexec permits the loading and execution of arbitrary code in ring 0, which permits the modification of the running kernel. Prevent this if trusted_kernel is true. Signed-off-by: Matthew Garrett --- kernel/kexec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/kexec.c b/kernel/kexec.c index 60bafbe..281ddd0 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -946,6 +947,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, if (!capable(CAP_SYS_BOOT) || kexec_load_disabled) return -EPERM; + if (get_trusted_kernel()) + return -EPERM; + /* * Verify we have a legal set of flags * This leaves us room for future extensions. -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/