4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Borislav Petkov <[email protected]> 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 <[email protected]> Tested-by: Bob Peterson <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andreas Gruenbacher <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Whitehouse <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: linux-mm <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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
