releases/4.4.133/efi-avoid-potential-crashes-fix-the-struct-efi_pci_io_protocol_32-definition-for-mixed-mode.patch

   1 From 0b3225ab9407f557a8e20f23f37aa7236c10a9b1 Mon Sep 17 00:00:00 2001
   2 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   3 Date: Fri, 4 May 2018 07:59:58 +0200
   4 Subject: efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' definition for mixed mode
   5
   6 From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
   7
   8 commit 0b3225ab9407f557a8e20f23f37aa7236c10a9b1 upstream.
   9
  10 Mixed mode allows a kernel built for x86_64 to interact with 32-bit
  11 EFI firmware, but requires us to define all struct definitions carefully
  12 when it comes to pointer sizes.
  13
  14 'struct efi_pci_io_protocol_32' currently uses a 'void *' for the
  15 'romimage' field, which will be interpreted as a 64-bit field
  16 on such kernels, potentially resulting in bogus memory references
  17 and subsequent crashes.
  18
  19 Tested-by: Hans de Goede <hdegoede@redhat.com>
  20 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
  21 Cc: <stable@vger.kernel.org>
  22 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  23 Cc: Matt Fleming <matt@codeblueprint.co.uk>
  24 Cc: Peter Zijlstra <peterz@infradead.org>
  25 Cc: Thomas Gleixner <tglx@linutronix.de>
  26 Cc: linux-efi@vger.kernel.org
  27 Link: http://lkml.kernel.org/r/20180504060003.19618-13-ard.biesheuvel@linaro.org
  28 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  29 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  30
  31 ---
  32  arch/x86/boot/compressed/eboot.c |    6 ++++--
  33  include/linux/efi.h              |    8 ++++----
  34  2 files changed, 8 insertions(+), 6 deletions(-)
  35
  36 --- a/arch/x86/boot/compressed/eboot.c
  37 +++ b/arch/x86/boot/compressed/eboot.c
  38 @@ -364,7 +364,8 @@ __setup_efi_pci32(efi_pci_io_protocol_32
  39         if (status != EFI_SUCCESS)
  40                 goto free_struct;
  41
  42 -       memcpy(rom->romdata, pci->romimage, pci->romsize);
  43 +       memcpy(rom->romdata, (void *)(unsigned long)pci->romimage,
  44 +              pci->romsize);
  45         return status;
  46
  47  free_struct:
  48 @@ -470,7 +471,8 @@ __setup_efi_pci64(efi_pci_io_protocol_64
  49         if (status != EFI_SUCCESS)
  50                 goto free_struct;
  51
  52 -       memcpy(rom->romdata, pci->romimage, pci->romsize);
  53 +       memcpy(rom->romdata, (void *)(unsigned long)pci->romimage,
  54 +              pci->romsize);
  55         return status;
  56
  57  free_struct:
  58 --- a/include/linux/efi.h
  59 +++ b/include/linux/efi.h
  60 @@ -364,8 +364,8 @@ typedef struct {
  61         u32 attributes;
  62         u32 get_bar_attributes;
  63         u32 set_bar_attributes;
  64 -       uint64_t romsize;
  65 -       void *romimage;
  66 +       u64 romsize;
  67 +       u32 romimage;
  68  } efi_pci_io_protocol_32;
  69
  70  typedef struct {
  71 @@ -384,8 +384,8 @@ typedef struct {
  72         u64 attributes;
  73         u64 get_bar_attributes;
  74         u64 set_bar_attributes;
  75 -       uint64_t romsize;
  76 -       void *romimage;
  77 +       u64 romsize;
  78 +       u64 romimage;
  79  } efi_pci_io_protocol_64;
  80
  81  typedef struct {