[PATCH v2 04/15] x86, kaslr: get kaslr_enabled back correctly

Yinghai Lu
2015-03-04T08:05:16Z

commit f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation")
is using address as value for kaslr_enabled.

That will random kaslr_enabled get that set or cleared.
Will have problem for system really have kaslr enabled.

-v2: update changelog.

Fixes: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation")
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
arch/x86/kernel/setup.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 98dc931..05d444f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -429,7 +429,13 @@ static void __init reserve_initrd(void)

static void __init parse_kaslr_setup(u64 pa_data, u32 data_len)
{
- kaslr_enabled = (bool)(pa_data + sizeof(struct setup_data));
+ /* kaslr_setup_data is defined in aslr.c */
+ unsigned char *data;
+ unsigned long offset = sizeof(struct setup_data);
+
+ data = early_memremap(pa_data, offset + 1);
+ kaslr_enabled = *(data + offset);
+ early_memunmap(data, offset + 1);
}

static void __init parse_setup_data(void)
--
1.8.4.5