From: Matthew Garrett <matthew.garrett@nebula.com>
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 <matthew.garrett@nebula.com>
Subject: [PATCH 08/12] kexec: Disable at runtime if securelevel has been set.
Date: Mon, 9 Sep 2013 11:49:42 -0400 [thread overview]
Message-ID: <1378741786-18430-9-git-send-email-matthew.garrett@nebula.com> (raw)
In-Reply-To: <1378741786-18430-1-git-send-email-matthew.garrett@nebula.com>
kexec permits the loading and execution of arbitrary code in ring 0, which
permits the modification of the running kernel. Prevent this if securelevel
has been set.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
---
kernel/kexec.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 59f7b55..98db2a1 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -32,6 +32,7 @@
#include <linux/vmalloc.h>
#include <linux/swap.h>
#include <linux/syscore_ops.h>
+#include <linux/security.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@@ -942,6 +943,9 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
if (!capable(CAP_SYS_BOOT))
return -EPERM;
+ if (get_securelevel() > 0)
+ return -EPERM;
+
/*
* Verify we have a legal set of flags
* This leaves us room for future extensions.
--
1.8.3.1
next prev parent reply other threads:[~2013-09-09 15:52 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-09 15:49 [PATCH 00/12] One more attempt at useful kernel lockdown Matthew Garrett
2013-09-09 15:49 ` [PATCH 01/12] Add BSD-style securelevel support Matthew Garrett
2013-09-09 16:27 ` H. Peter Anvin
2013-09-09 16:30 ` Matthew Garrett
2013-09-09 16:42 ` H. Peter Anvin
2013-09-09 16:44 ` Matthew Garrett
2013-09-09 16:51 ` H. Peter Anvin
2013-09-09 16:55 ` Matthew Garrett
2013-09-09 18:31 ` Matthew Garrett
2013-09-09 15:49 ` [PATCH 02/12] Enforce module signatures when securelevel is greater than 0 Matthew Garrett
2013-09-09 15:49 ` [PATCH 03/12] PCI: Lock down BAR access when securelevel is enabled Matthew Garrett
2013-09-09 15:49 ` [PATCH 04/12] x86: Lock down IO port " Matthew Garrett
2013-09-09 15:49 ` [PATCH 05/12] Restrict /dev/mem and /dev/kmem when securelevel is set Matthew Garrett
2013-09-09 15:49 ` [PATCH 06/12] acpi: Limit access to custom_method if " Matthew Garrett
2013-09-09 15:49 ` [PATCH 07/12] acpi: Ignore acpi_rsdp kernel parameter when " Matthew Garrett
2013-11-26 12:54 ` Josh Boyer
2013-09-09 15:49 ` Matthew Garrett [this message]
2013-09-09 15:49 ` [PATCH 09/12] uswsusp: Disable " Matthew Garrett
2013-09-09 15:49 ` [PATCH 10/12] x86: Restrict MSR access " Matthew Garrett
2013-09-09 15:49 ` [PATCH 11/12] asus-wmi: Restrict debugfs interface " Matthew Garrett
2013-09-09 15:49 ` [PATCH 12/12] Add option to automatically set securelevel when in Secure Boot mode Matthew Garrett
2013-09-09 17:18 ` [PATCH 00/12] One more attempt at useful kernel lockdown Valdis.Kletnieks
2013-09-09 17:24 ` Matthew Garrett
2013-09-09 18:25 ` David Lang
2013-09-09 18:28 ` Matthew Garrett
2013-09-09 18:40 ` David Lang
2013-09-09 18:42 ` Matthew Garrett
2013-09-09 18:53 ` David Lang
2013-09-09 19:06 ` Matthew Garrett
2013-09-09 19:59 ` David Lang
2013-09-09 20:06 ` Matthew Garrett
2013-09-09 20:15 ` David Lang
2013-09-09 20:17 ` Matthew Garrett
2013-09-09 19:01 ` Valdis.Kletnieks
2013-09-09 19:08 ` Matthew Garrett
2013-09-09 19:41 ` H. Peter Anvin
2013-09-09 19:52 ` Josh Boyer
2013-09-09 19:56 ` H. Peter Anvin
2013-09-09 19:58 ` Josh Boyer
2013-09-09 20:02 ` H. Peter Anvin
2013-09-09 20:10 ` David Lang
2013-09-09 20:13 ` Josh Boyer
2013-09-09 23:02 ` Matthew Garrett
2013-09-09 23:19 ` David Lang
2013-09-09 23:20 ` Kees Cook
2013-09-09 23:30 ` James Bottomley
2013-09-09 23:34 ` Kees Cook
2013-09-10 0:53 ` Matthew Garrett
2013-09-10 2:44 ` David Lang
2013-09-10 2:55 ` Matthew Garrett
2013-09-10 3:09 ` David Lang
2013-09-10 3:53 ` Matthew Garrett
2013-09-10 17:23 ` Henrique de Moraes Holschuh
2013-09-10 18:26 ` Matthew Garrett
2013-09-10 18:29 ` H. Peter Anvin
2013-09-10 18:51 ` gregkh
2013-09-10 18:55 ` Kees Cook
2013-09-10 19:17 ` David Lang
2013-09-10 19:44 ` H. Peter Anvin
2013-09-10 23:43 ` Mimi Zohar
2013-09-10 23:48 ` H. Peter Anvin
2013-09-10 23:55 ` Mimi Zohar
2013-09-10 23:58 ` H. Peter Anvin
2013-09-10 18:48 ` Kees Cook
2013-09-11 9:32 ` joeyli
2013-09-09 20:30 ` Mimi Zohar
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