From mboxrd@z Thu Jan 1 00:00:00 1970 From: 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> References: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> Return-path: In-Reply-To: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-efi@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