We were truncating the image offset within the target image to 16 bits which again meant that we were potentially overwriting random memory in the lower 16 bits of the image.
This patch casts the offset to a more reasonable 32bits.
With this applied, I can successfully see Shell.efi assert because it can't find a protocol it expects to be available.
Signed-off-by: Alexander Graf agraf@suse.de --- lib/efi_loader/efi_image_loader.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index 574b204..5165377 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -37,7 +37,7 @@ static void efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel, const uint16_t *relocs = (const uint16_t *)(rel + 1); i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t); while (i--) { - uint16_t offset = (*relocs & 0xfff) + + uint32_t offset = (uint32_t)(*relocs & 0xfff) + rel->VirtualAddress; int type = *relocs >> EFI_PAGE_SHIFT; unsigned long delta = (unsigned long)efi_reloc;