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From: Matthew Garrett <mjg@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org,
	Matthew Garrett <mjg@redhat.com>
Subject: [PATCH 07/11] kexec: Disable in a secure boot environment
Date: Tue,  4 Sep 2012 11:55:13 -0400	[thread overview]
Message-ID: <1346774117-2277-8-git-send-email-mjg@redhat.com> (raw)
In-Reply-To: <1346774117-2277-1-git-send-email-mjg@redhat.com>

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@redhat.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


  parent reply	other threads:[~2012-09-04 15:56 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-04 15:55 [RFC] First attempt at kernel secure boot support Matthew Garrett
2012-09-04 15:55 ` [PATCH 01/11] Secure boot: Add new capability Matthew Garrett
2012-09-04 15:55 ` [PATCH 02/11] PCI: Lock down BAR access in secure boot environments Matthew Garrett
2012-10-01 21:00   ` Pavel Machek
2012-09-04 15:55 ` [PATCH 03/11] x86: Lock down IO port " Matthew Garrett
2012-09-04 16:16   ` Alan Cox
2012-09-04 16:16     ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 04/11] ACPI: Limit access to custom_method Matthew Garrett
2012-09-04 15:55 ` [PATCH 05/11] asus-wmi: Restrict debugfs interface Matthew Garrett
2012-09-04 16:12   ` Alan Cox
2012-09-04 16:13     ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 06/11] Restrict /dev/mem and /dev/kmem in secure boot setups Matthew Garrett
2012-09-04 15:55 ` Matthew Garrett [this message]
2012-09-04 20:13   ` [PATCH 07/11] kexec: Disable in a secure boot environment Eric W. Biederman
2012-09-04 20:22     ` Matthew Garrett
2012-09-04 21:13       ` Eric W. Biederman
2012-09-04 21:27         ` Matthew Garrett
2012-09-04 22:12           ` Eric W. Biederman
2012-09-04 23:25             ` Matthew Garrett
2012-09-05  4:33               ` Eric W. Biederman
2012-09-05  5:16                 ` Matthew Garrett
2012-09-05  7:00                   ` Eric W. Biederman
2012-09-05  7:03                     ` Matthew Garrett
2012-09-04 21:39         ` Alan Cox
2012-09-04 21:40           ` Matthew Garrett
2012-09-05 15:43             ` Roland Eggner
2012-09-05 15:46               ` Matthew Garrett
2012-09-05 21:13   ` Mimi Zohar
2012-09-05 21:41     ` Matthew Garrett
2012-09-05 21:49       ` Eric Paris
2012-09-04 15:55 ` [PATCH 08/11] Secure boot: Add a dummy kernel parameter that will switch on Secure Boot mode Matthew Garrett
2012-09-04 15:55 ` [PATCH 09/11] efi: Enable secure boot lockdown automatically when enabled in firmware Matthew Garrett
2012-09-04 15:55 ` [PATCH 10/11] acpi: Ignore acpi_rsdp kernel parameter in a secure boot environment Matthew Garrett
2012-09-04 16:30   ` Shuah Khan
2012-09-04 16:38     ` Matthew Garrett
2012-09-04 16:44       ` Shuah Khan
2012-09-04 20:37         ` Alan Cox
2012-09-04 20:37           ` Matthew Garrett
2012-09-04 20:50             ` Josh Boyer
2012-09-04 15:55 ` [PATCH 11/11] SELinux: define mapping for new Secure Boot capability Matthew Garrett
2012-09-04 16:08 ` [RFC] First attempt at kernel secure boot support Alan Cox
2012-09-04 16:12   ` Matthew Garrett
2012-10-01 21:07     ` Pavel Machek

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