[PATCH] nx-emu: fix inverted report of disable_nx

[Kees Cook]

This nx-emu commit:
http://git.kernel.org/?p=linux/kernel/git/frob/linux-2.6-roland.git;a=com...
was intended to replace "exec_shield" with "!disable_nx", but in
x86_report_nx() it was not correctly inverted resulting in a backward
report to dmesg about the state of nx-emu.

Signed-off-by: Kees Cook <kees.cook(a)canonical.com&gt;
---
 arch/x86/mm/setup_nx.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index b936b25..1d7a269 100644
--- a/arch/x86/mm/setup_nx.c
+++ b/arch/x86/mm/setup_nx.c
@@ -42,7 +42,7 @@ void __init x86_report_nx(void)
 {
 	if (!cpu_has_nx) {
 #ifdef CONFIG_X86_32
-		if (disable_nx)
+		if (!disable_nx)
 			printk(KERN_INFO "NX (Execute Disable) protection: "
 			       "approximated by x86 segment limits\n");
 		else
-- 
1.7.2.3


-- 
Kees Cook
Ubuntu Security Team

[Kyle McMartin]

On Sat, Nov 20, 2010 at 11:03:42PM -0800, Kees Cook wrote:
>  This nx-emu commit:
>
> http://git.kernel.org/?p=linux/kernel/git/frob/linux-2.6-roland.git;a=com...
>  was intended to replace "exec_shield" with "!disable_nx", but in
>  x86_report_nx() it was not correctly inverted resulting in a backward
>  report to dmesg about the state of nx-emu.
>  
>  Signed-off-by: Kees Cook <kees.cook(a)canonical.com&gt; 
Thanks, applied (to Fedora at least.)

--Kyle

[Roland McGrath]

I merged it into my fedora/x86-nx-emulation tree.

Thanks,
Roland