4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Borislav Petkov <b...@suse.de>
commit 1c27f646b18fb56308dff82784ca61951bad0b48 upstream.
We needed the physical address of the container in order to compute the
offset within the relocated ramdisk. And we did this by doing __pa() on
the virtual address.
However, __pa() does checks whether the physical address is within
PAGE_OFFSET and __START_KERNEL_map - see __phys_addr() - which fail
if we have CONFIG_RANDOMIZE_MEMORY enabled: we feed a virtual address
which *doesn't* have the randomization offset into a function which uses
PAGE_OFFSET which *does* have that offset.
This makes this check fire:
VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
^^^^^^
due to the randomization offset.
The fix is as simple as using __pa_nodebug() because we do that
randomization offset accounting later in that function ourselves.
Reported-by: Bob Peterson <rpete...@redhat.com>
Tested-by: Bob Peterson <rpete...@redhat.com>
Signed-off-by: Borislav Petkov <b...@suse.de>
Cc: Andreas Gruenbacher <agrue...@redhat.com>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Mel Gorman <mgor...@techsingularity.net>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Steven Whitehouse <swhit...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: linux-mm <linux...@kvack.org>
Link: http://lkml.kernel.org/r/20161027123623.j2jri5bandimb...@pd.tnic
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/kernel/cpu/microcode/amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -429,7 +429,7 @@ int __init save_microcode_in_initrd_amd(
* We need the physical address of the container for both bitness since
* boot_params.hdr.ramdisk_image is a physical address.
*/
- cont = __pa(container);
+ cont = __pa_nodebug(container);
cont_va = container;
#endif
