This is a note to let you know that I've just added the patch titled
x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY=y
to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-microcode-amd-fix-more-fallout-from-config_randomize_memory-y.patch
and it can be found in the queue-4.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1c27f646b18fb56308dff82784ca61951bad0b48 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@xxxxxxx>
Date: Thu, 27 Oct 2016 14:36:23 +0200
Subject: x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY=y
From: Borislav Petkov <bp@xxxxxxx>
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 <rpeterso@xxxxxxxxxx>
Tested-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Whitehouse <swhiteho@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-mm <linux-mm@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20161027123623.j2jri5bandimboff@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.8/x86-microcode-amd-fix-more-fallout-from-config_randomize_memory-y.patch
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