commit 906f6858218fd892463bf964888328c3f6f26135
author Heinrich Schuchardt <xypron.glpk@gmx.de> Sat May 11 08:21:17 2019 +0200
committer Heinrich Schuchardt <xypron.glpk@gmx.de> Sun May 12 20:54:22 2019 +0200
tree 9462ec2536eabca5da0e8600822bb7e5fc77b075
parent 5c304fcb3f0125b66c2b108b3411a0efe3fe6541

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>

lib/efi_loader/efi_memory.c

diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index adbeb1d..11d5547 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -330,10 +330,11 @@
  * 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 @@
 		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 @@
 		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 @@
 	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 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;