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Commit 0b3225ab authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
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efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' definition for mixed mode 



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: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180504060003.19618-13-ard.biesheuvel@linaro.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 67b8d5c7

arch/x86/boot/compressed/eboot.c

+4 −2
Original line number Diff line number Diff line
@@ -163,7 +163,8 @@ __setup_efi_pci32(efi_pci_io_protocol_32 *pci, struct pci_setup_rom **__rom) 
	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:
@@ -269,7 +270,8 @@ __setup_efi_pci64(efi_pci_io_protocol_64 *pci, struct pci_setup_rom **__rom) 
	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:

include/linux/efi.h

+4 −4
Original line number Diff line number Diff line
@@ -395,8 +395,8 @@ 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 {
@@ -415,8 +415,8 @@ 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 {