4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ard.biesheuvel@linaro.org
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 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 @@ -364,7 +364,8 @@ __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: @@ -470,7 +471,8 @@ __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 @@ -364,8 +364,8 @@ 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 { @@ -384,8 +384,8 @@ 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 {