linux-kernel - [PATCH 07/11] kexec: Disable in a secure boot environment

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Message-Id: <1346774117-2277-8-git-send-email-mjg@redhat.com>
Date:	Tue,  4 Sep 2012 11:55:13 -0400
From:	Matthew Garrett <mjg@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-security-module@...r.kernel.org, linux-efi@...r.kernel.org,
	Matthew Garrett <mjg@...hat.com>
Subject: [PATCH 07/11] kexec: Disable in a secure boot environment

kexec could be used as a vector for a malicious user to use a signed kernel
to circumvent the secure boot trust model. In the long run we'll want to
support signed kexec payloads, but for the moment we should just disable
loading entirely in that situation.

Signed-off-by: Matthew Garrett <mjg@...hat.com>
---
 kernel/kexec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 0668d58..48852ec 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -944,7 +944,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 	int result;
 
 	/* We only trust the superuser with rebooting the system. */
-	if (!capable(CAP_SYS_BOOT))
+	if (!capable(CAP_SYS_BOOT) || !capable(CAP_SECURE_FIRMWARE))
 		return -EPERM;
 
 	/*
-- 
1.7.11.4

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