Re: [PATCH 08/10] kexec: Disable at runtime if the kernel enforces module loading restrictions

2013-09-01 Thread Geert Uytterhoeven 
On Mon, Aug 19, 2013 at 6:10 PM, Matthew Garrett
matthew.garr...@nebula.com wrote:
 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.

Any plans for signed kexec code?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

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[PATCH 08/10] kexec: Disable at runtime if the kernel enforces module loading restrictions

2013-08-19 Thread Matthew Garrett 
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.garr...@nebula.com
---
 kernel/kexec.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 59f7b55..1a7690f 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/module.h
 
 #include asm/page.h
 #include asm/uaccess.h
@@ -1645,6 +1646,9 @@ int kernel_kexec(void)
goto Unlock;
}
 
+   if (secure_modules())
+   return -EPERM;
+
 #ifdef CONFIG_KEXEC_JUMP
if (kexec_image-preserve_context) {
lock_system_sleep();
-- 
1.8.3.1

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