From b1237c6e8afa3f112128a886faed152e65def3fd Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Thu, 18 Aug 2016 23:45:18 +0200 Subject: [PATCH] efi_loader: Fix relocations above 64kb image size 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 --- 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 574b204f23..5165377eee 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; -- 2.25.1