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. efi_pci_io_protocol32 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.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/x86/boot/compressed/eboot.c | 6 ++++--
include/linux/efi.h | 8 ++++----
2 files changed, 8 insertions(+), 6 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:
diff --git a/include/linux/efi.h b/include/linux/efi.h
index f1b7d68ac460..3016d8c456bc 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -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 {
--
2.17.0
--
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