From 55af40a5781f1de574822745c9c76b3a928388cd Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 30 May 2020 07:35:59 +0200 Subject: [PATCH] efi_loader: simplify PE consistency check Knowing that at least one section header follows the optional header we only need to check for the length of the 64bit header which is longer than the 32bit header. Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_image_loader.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c index c273287..478aaf5 100644 --- a/lib/efi_loader/efi_image_loader.c +++ b/lib/efi_loader/efi_image_loader.c @@ -637,21 +637,18 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle, goto err; } - /* assume sizeof(IMAGE_NT_HEADERS32) <= sizeof(IMAGE_NT_HEADERS64) */ - if (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32)) { + /* + * Check if the image section header fits into the file. Knowing that at + * least one section header follows we only need to check for the length + * of the 64bit header which is longer than the 32bit header. + */ + if (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS64)) { printf("%s: Invalid offset for Extended Header\n", __func__); ret = EFI_LOAD_ERROR; goto err; } nt = (void *) ((char *)efi + dos->e_lfanew); - if ((nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) && - (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS64))) { - printf("%s: Invalid offset for Extended Header\n", __func__); - ret = EFI_LOAD_ERROR; - goto err; - } - if (nt->Signature != IMAGE_NT_SIGNATURE) { printf("%s: Invalid NT Signature\n", __func__); ret = EFI_LOAD_ERROR; -- 2.7.4