x86/efi: Initialize status to ensure garbage is not returned on small size

Colin Ian King · mfleming · commit ac0e94b63e65 · 2016-09-09T16:08:44.000+01:00
Although very unlikey, if size is too small or zero, then we end up with
status not being set and returning garbage. Instead, initializing status to
EFI_INVALID_PARAMETER to indicate that size is invalid in the calls to
setup_uga32 and setup_uga64.

Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
@@ -578,7 +578,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
 	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 	unsigned long nr_ugas;
 	u32 *handles = (u32 *)uga_handle;;
-	efi_status_t status;
+	efi_status_t status = EFI_INVALID_PARAMETER;
 	int i;
 
 	first_uga = NULL;
@@ -623,7 +623,7 @@ setup_uga64(void **uga_handle, unsigned long size, u32 *width, u32 *height)
 	efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
 	unsigned long nr_ugas;
 	u64 *handles = (u64 *)uga_handle;;
-	efi_status_t status;
+	efi_status_t status = EFI_INVALID_PARAMETER;
 	int i;
 
 	first_uga = NULL;
