3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ard Biesheuvel <[email protected]>

commit 0b3225ab9407f557a8e20f23f37aa7236c10a9b1 upstream.

Mixed mode allows a kernel built for x86_64 to interact with 32-bit
EFI firmware, but requires us to define all struct definitions carefully
when it comes to pointer sizes.

'struct efi_pci_io_protocol_32' currently uses a 'void *' for the
'romimage' field, which will be interpreted as a 64-bit field
on such kernels, potentially resulting in bogus memory references
and subsequent crashes.

Tested-by: Hans de Goede <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Cc: <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [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/boot/compressed/eboot.c |    6 ++++--
 include/linux/efi.h              |    8 ++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -365,7 +365,8 @@ __setup_efi_pci32(efi_pci_io_protocol_32
        if (status != EFI_SUCCESS)
                goto free_struct;
 
-       memcpy(rom->romdata, pci->romimage, pci->romsize);
+       memcpy(rom->romdata, (void *)(unsigned long)pci->romimage,
+              pci->romsize);
        return status;
 
 free_struct:
@@ -471,7 +472,8 @@ __setup_efi_pci64(efi_pci_io_protocol_64
        if (status != EFI_SUCCESS)
                goto free_struct;
 
-       memcpy(rom->romdata, pci->romimage, pci->romsize);
+       memcpy(rom->romdata, (void *)(unsigned long)pci->romimage,
+              pci->romsize);
        return status;
 
 free_struct:
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -360,8 +360,8 @@ typedef struct {
        u32 attributes;
        u32 get_bar_attributes;
        u32 set_bar_attributes;
-       uint64_t romsize;
-       void *romimage;
+       u64 romsize;
+       u32 romimage;
 } efi_pci_io_protocol_32;
 
 typedef struct {
@@ -380,8 +380,8 @@ typedef struct {
        u64 attributes;
        u64 get_bar_attributes;
        u64 set_bar_attributes;
-       uint64_t romsize;
-       void *romimage;
+       u64 romsize;
+       u64 romimage;
 } efi_pci_io_protocol_64;
 
 typedef struct {


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