Carve out a function to check that a buffer contains a PE-COFF image.
Signed-off-by: Heinrich Schuchardt <xypron.g...@gmx.de>
---
include/efi_loader.h | 2 +
lib/efi_loader/efi_image_loader.c | 80 ++++++++++++++++++-------------
2 files changed, 48 insertions(+), 34 deletions(-)
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 0fc2255f3f..63459ea649 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -453,6 +453,8 @@ efi_status_t efi_set_watchdog(unsigned long timeout);
/* Called from places to check whether a timer expired */
void efi_timer_check(void);
+/* Check if a buffer contains a PE-COFF image */
+efi_status_t efi_check_pe(void *buffer, size_t size, void **nt_header);
/* PE loader implementation */
efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
void *efi, size_t efi_size,
diff --git a/lib/efi_loader/efi_image_loader.c
b/lib/efi_loader/efi_image_loader.c
index 94f76ef6b8..d4dd9e9433 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -675,6 +675,46 @@ static bool efi_image_authenticate(void *efi, size_t
efi_size)
}
#endif /* CONFIG_EFI_SECURE_BOOT */
+
+/**
+ * efi_check_pe() - check if a memory buffer contains a PE-COFF image
+ *
+ * @buffer: buffer to check
+ * @size: size of buffer
+ * @nt_header: on return pointer to NT header of PE-COFF image
+ * Return: EFI_SUCCESS if the buffer contains a PE-COFF image
+ */
+efi_status_t efi_check_pe(void *buffer, size_t size, void **nt_header)
+{
+ IMAGE_DOS_HEADER *dos = buffer;
+ IMAGE_NT_HEADERS32 *nt;
+
+ if (size < sizeof(*dos))
+ return EFI_INVALID_PARAMETER;
+
+ /* Check for DOS magix */
+ if (dos->e_magic != IMAGE_DOS_SIGNATURE)
+ return EFI_INVALID_PARAMETER;
+
+ /*
+ * 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 (size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32))
+ return EFI_INVALID_PARAMETER;
+ nt = (IMAGE_NT_HEADERS32 *)((u8 *)buffer + dos->e_lfanew);
+
+ /* Check for PE-COFF magic */
+ if (nt->Signature != IMAGE_NT_SIGNATURE)
+ return EFI_INVALID_PARAMETER;
+
+ if (nt_header)
+ *nt_header = nt;
+
+ return EFI_SUCCESS;
+}
+
/**
* efi_load_pe() - relocate EFI binary
*
@@ -705,36 +745,10 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj
*handle,
int supported = 0;
efi_status_t ret;
- /* Sanity check for a file header */
- if (efi_size < sizeof(*dos)) {
- log_err("Truncated DOS Header\n");
- ret = EFI_LOAD_ERROR;
- goto err;
- }
-
- dos = efi;
- if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
- log_err("Invalid DOS Signature\n");
- ret = EFI_LOAD_ERROR;
- goto err;
- }
-
- /*
- * 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)) {
- log_err("Invalid offset for Extended Header\n");
- ret = EFI_LOAD_ERROR;
- goto err;
- }
-
- nt = (void *) ((char *)efi + dos->e_lfanew);
- if (nt->Signature != IMAGE_NT_SIGNATURE) {
- log_err("Invalid NT Signature\n");
- ret = EFI_LOAD_ERROR;
- goto err;
+ ret = efi_check_pe(efi, efi_size, (void **)&nt);
+ if (ret != EFI_SUCCESS) {
+ log_err("Not a PE-COFF file\n");
+ return EFI_LOAD_ERROR;
}
for (i = 0; machines[i]; i++)
@@ -746,8 +760,7 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj
*handle,
if (!supported) {
log_err("Machine type 0x%04x is not supported\n",
nt->FileHeader.Machine);
- ret = EFI_LOAD_ERROR;
- goto err;
+ return EFI_LOAD_ERROR;
}
num_sections = nt->FileHeader.NumberOfSections;
@@ -757,8 +770,7 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj
*handle,
if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections
- efi)) {
log_err("Invalid number of sections: %d\n", num_sections);
- ret = EFI_LOAD_ERROR;
- goto err;
+ return EFI_LOAD_ERROR;
}
/* Authenticate an image */
--
2.29.2
