efi_loader: AllocateAdress error handling

If AllocatePages() is called with AllocateAddress, the UEFI spec requires
to return EFI_NOT_FOUND in case the memory page does not exist.

The UEFI SCT II 2017 spec additionally requires to return EFI_NOT_FOUND if
the page is already allocated.

Check that *Memory refers to an unallocated page.

UEFI SCT II (2017): AllocatePages(), 5.1.2.1.9 - 5.1.2.1.10

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index adbeb1d..11d5547 100644 (file)
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -330,10 +330,11 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
  * Page alignment is not checked as this is not a requirement of
  * efi_free_pool().
  *
- * @addr:      address of page to be freed
- * Return:     status code
+ * @addr:              address of page to be freed
+ * @must_be_allocated: return success if the page is allocated
+ * Return:             status code
  */
-static efi_status_t efi_check_allocated(u64 addr)
+static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated)
 {
        struct efi_mem_list *item;
 
@@ -344,7 +345,8 @@ static efi_status_t efi_check_allocated(u64 addr)
                u64 end = start + (item->desc.num_pages << EFI_PAGE_SHIFT);
 
                if (addr >= start && addr < end) {
-                       if (item->desc.type != EFI_CONVENTIONAL_MEMORY)
+                       if (must_be_allocated ^
+                           (item->desc.type == EFI_CONVENTIONAL_MEMORY))
                                return EFI_SUCCESS;
                        else
                                return EFI_NOT_FOUND;
@@ -438,6 +440,11 @@ efi_status_t efi_allocate_pages(int type, int memory_type,
                break;
        case EFI_ALLOCATE_ADDRESS:
                /* Exact address, reserve it. The addr is already in *memory. */
+               r = efi_check_allocated(*memory, false);
+               if (r != EFI_SUCCESS) {
+                       r = EFI_NOT_FOUND;
+                       break;
+               }
                addr = *memory;
                break;
        default:
@@ -488,7 +495,7 @@ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
        uint64_t r = 0;
        efi_status_t ret;
 
-       ret = efi_check_allocated(memory);
+       ret = efi_check_allocated(memory, true);
        if (ret != EFI_SUCCESS)
                return ret;
 
@@ -555,7 +562,7 @@ efi_status_t efi_free_pool(void *buffer)
        efi_status_t ret;
        struct efi_pool_allocation *alloc;
 
-       ret = efi_check_allocated((uintptr_t)buffer);
+       ret = efi_check_allocated((uintptr_t)buffer, true);
        if (ret != EFI_SUCCESS)
                return ret;