UBUNTU: SAUCE: arch/x86/entry/vdso: temporarily disable vdso

Currently running KVM/QEMU with vdso enabled trips a segfault on
vdso access inside the virtual machine. Force the default vdso
setting off to workaround this issue. It is our expecation to
revert this once we have figured out the root issue.

CVE-2017-5754
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/entry/vdso/vdso32-setup.c

@@ -17,7 +17,7 @@
 #ifdef CONFIG_COMPAT_VDSO
 #define VDSO_DEFAULT	0
 #else
-#define VDSO_DEFAULT	1
+#define VDSO_DEFAULT	0
 #endif
 
 /*

arch/x86/entry/vdso/vma.c

@@ -22,7 +22,7 @@
 #include <asm/cpufeature.h>
 
 #if defined(CONFIG_X86_64)
-unsigned int __read_mostly vdso64_enabled = 1;
+unsigned int __read_mostly vdso64_enabled = 0;
 #endif
 
 void __init init_vdso_image(const struct vdso_image *image)