efi/x86: Fix boot regression on systems with invalid memmap entries

59365cad · Ard Biesheuvel <[email protected]> · 2020-02-02 00:33:04 +01:00

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 <[email protected]>
Tested-by: Jörg Otte <[email protected]>
Tested-by: Dan Williams <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]

Commit: 59365cadfbcd299b8cdbe0c165faf15767c5f166
Parents: b3a60822

Changes

1 files changed · +1 −1

File	Status	Add	Del	Content
arch/x86/platform/efi/efi.c	modified	+1	−1	View file

arch/x86/platform/efi/efi.c

View file

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 59f7f6d..ae923ee 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -308,7 +308,7 @@ 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,
 		};
 