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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-05-04 07:59:58 +0200
committerIngo Molnar <mingo@kernel.org>2018-05-14 08:56:29 +0200
commit0b3225ab9407f557a8e20f23f37aa7236c10a9b1 (patch)
tree22d16961238b4d1afd1b8813229ce001956889f6 /arch/x86/boot
parent67b8d5c7081221efa252e111cd52532ec6d4266f (diff)
downloadlinux-0b3225ab9407f557a8e20f23f37aa7236c10a9b1.tar.gz
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: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ard 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot')
-rw-r--r--arch/x86/boot/compressed/eboot.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 47d3efff6805..09f36c0d9d4f 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -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: