From: Ard Biesheuvel <ardb@kernel.org>
Date: Sun, 2 Feb 2020 00:33:04 +0100
Subject: efi/x86: Fix boot regression on systems with invalid memmap entries
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Patch-mainline: v5.6-rc1
Git-commit: 59365cadfbcd299b8cdbe0c165faf15767c5f166
References: jsc#SLE-16407

In efi_clean_memmap(), we do a pass over the EFI memory map to remove
bogus entries that may be returned on certain systems.

This recent commit:

  1db91035d01aa8bf ("efi: Add tracking for dynamically allocated memmaps")

refactored this code to pass the input to efi_memmap_install() via a
temporary struct on the stack, which is populated using an initializer
which inadvertently defines the value of its size field in terms of its
desc_size field, which value cannot be relied upon yet in the initializer
itself.

Fix this by using efi.memmap.desc_size instead, which is where we get
the value for desc_size from in the first place.

Reported-by: Jörg Otte <jrg.otte@gmail.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: jrg.otte@gmail.com
Cc: torvalds@linux-foundation.org
Cc: mingo@kernel.org
Link: https://lore.kernel.org/r/20200201233304.18322-1-ardb@kernel.org
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 arch/x86/platform/efi/efi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -309,7 +309,7 @@ static void __init efi_clean_memmap(void
 			.phys_map = efi.memmap.phys_map,
 			.desc_version = efi.memmap.desc_version,
 			.desc_size = efi.memmap.desc_size,
-			.size = data.desc_size * (efi.memmap.nr_map - n_removal),
+			.size = efi.memmap.desc_size * (efi.memmap.nr_map - n_removal),
 			.flags = 0,
 		};