Allow memory allocated by handle_image() to be freed

There is currently no way for a caller of handle_image() to free the
memory allocated to hold the relocated executable.  Fix by adding the
allocated memory address and number of pages as returned parameters
from handle_image().

Signed-off-by: Michael Brown <mbrown@fensystems.co.uk>

diff --git a/shim.c b/shim.c
index a45cbf5d51ec61516e843bd4d5eb95a8a00c50b4..bfcfd382c58b8cae8026e58d89de7a02e61a10e4 100644 (file)
--- a/shim.c
+++ b/shim.c
@@ -1221,7 +1221,9 @@ static EFI_STATUS read_header(void *data, unsigned int datasize,
  */
 static EFI_STATUS handle_image (void *data, unsigned int datasize,
                                EFI_LOADED_IMAGE *li,
-                               EFI_IMAGE_ENTRY_POINT *entry_point)
+                               EFI_IMAGE_ENTRY_POINT *entry_point,
+                               EFI_PHYSICAL_ADDRESS *alloc_address,
+                               UINTN *alloc_pages)
 {
        EFI_STATUS efi_status;
        char *buffer;
@@ -1230,7 +1232,6 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
        char *base, *end;
        PE_COFF_LOADER_IMAGE_CONTEXT context;
        unsigned int alignment, alloc_size;
-       EFI_PHYSICAL_ADDRESS alloc_address;
        int found_entry_point = 0;
        UINT8 sha1hash[SHA1_DIGEST_SIZE];
        UINT8 sha256hash[SHA256_DIGEST_SIZE];
@@ -1293,22 +1294,23 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
 
        alloc_size = ALIGN_VALUE(context.ImageSize + context.SectionAlignment,
                                 PAGE_SIZE);
+       *alloc_pages = alloc_size / PAGE_SIZE;
 
        efi_status = gBS->AllocatePages(AllocateAnyPages, EfiLoaderCode,
-                                       alloc_size / PAGE_SIZE, &alloc_address);
+                                       *alloc_pages, alloc_address);
        if (EFI_ERROR(efi_status)) {
                perror(L"Failed to allocate image buffer\n");
                return EFI_OUT_OF_RESOURCES;
        }
 
-       buffer = (void *)ALIGN_VALUE((unsigned long)alloc_address, alignment);
+       buffer = (void *)ALIGN_VALUE((unsigned long)*alloc_address, alignment);
 
        CopyMem(buffer, data, context.SizeOfHeaders);
 
        *entry_point = ImageAddress(buffer, context.ImageSize, context.EntryPoint);
        if (!*entry_point) {
                perror(L"Entry point is invalid\n");
-               gBS->FreePages(alloc_address, alloc_size / PAGE_SIZE);
+               gBS->FreePages(*alloc_address, *alloc_pages);
                return EFI_UNSUPPORTED;
        }
 
@@ -1342,7 +1344,7 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
 
                if (end < base) {
                        perror(L"Section %d has negative size\n", i);
-                       gBS->FreePages(alloc_address, alloc_size / PAGE_SIZE);
+                       gBS->FreePages(*alloc_address, *alloc_pages);
                        return EFI_UNSUPPORTED;
                }
 
@@ -1811,6 +1813,8 @@ EFI_STATUS start_image(EFI_HANDLE image_handle, CHAR16 *ImagePath)
        EFI_STATUS efi_status;
        EFI_LOADED_IMAGE *li, li_bak;
        EFI_IMAGE_ENTRY_POINT entry_point;
+       EFI_PHYSICAL_ADDRESS alloc_address;
+       UINTN alloc_pages;
        CHAR16 *PathName = NULL;
        void *sourcebuffer = NULL;
        UINT64 sourcesize = 0;
@@ -1894,7 +1898,8 @@ EFI_STATUS start_image(EFI_HANDLE image_handle, CHAR16 *ImagePath)
        /*
         * Verify and, if appropriate, relocate and execute the executable
         */
-       efi_status = handle_image(data, datasize, li, &entry_point);
+       efi_status = handle_image(data, datasize, li, &entry_point,
+                                 &alloc_address, &alloc_pages);
        if (EFI_ERROR(efi_status)) {
                perror(L"Failed to load image: %r\n", efi_status);
                PrintErrors();