kernel/kexec-Disable-at-runtime-if-the-kernel-enforces-modu.patch
Josh Boyer 208228cebd Linux v3.19-rc2
- Temporarily disable aarch64patches
- Happy New Year
2015-01-05 16:09:49 -05:00

44 lines
1.2 KiB
Diff

From: Matthew Garrett <matthew.garrett@nebula.com>
Date: Fri, 9 Aug 2013 03:33:56 -0400
Subject: [PATCH] kexec: Disable at runtime if the kernel enforces module
loading restrictions
kexec permits the loading and execution of arbitrary code in ring 0, which
is something that module signing enforcement is meant to prevent. It makes
sense to disable kexec in this situation.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
---
kernel/kexec.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 9a8a01abbaed..9a0ecbf14545 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -36,6 +36,7 @@
#include <linux/syscore_ops.h>
#include <linux/compiler.h>
#include <linux/hugetlb.h>
+#include <linux/module.h>
#include <asm/page.h>
#include <asm/uaccess.h>
@@ -1251,6 +1252,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
return -EPERM;
/*
+ * kexec can be used to circumvent module loading restrictions, so
+ * prevent loading in that case
+ */
+ if (secure_modules())
+ return -EPERM;
+
+ /*
* Verify we have a legal set of flags
* This leaves us room for future extensions.
*/
--
2.1.0