[PATCH 2/2] efi_runtime: add checking variable_name input

[Ivan Hu]

Add checking variable name userspace input before copy from it.

Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
---
 efi_runtime/efi_runtime.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/efi_runtime/efi_runtime.c b/efi_runtime/efi_runtime.c
index 86076d3..4f2b372 100644
--- a/efi_runtime/efi_runtime.c
+++ b/efi_runtime/efi_runtime.c
@@ -251,7 +251,7 @@ static long efi_runtime_set_variable(unsigned long arg)
 	struct efi_setvariable setvariable_local;
 	efi_guid_t vendor_guid;
 	efi_status_t status;
-	uint16_t *name;
+	uint16_t *name = NULL;
 	void *data;
 	int rv;
 
@@ -264,9 +264,11 @@ static long efi_runtime_set_variable(unsigned long arg)
 			   sizeof(vendor_guid)))
 		return -EFAULT;
 
-	rv = copy_ucs2_from_user(&name, setvariable_local.variable_name);
-	if (rv)
-		return rv;
+	if (setvariable_local.variable_name) {
+		rv = copy_ucs2_from_user(&name, setvariable_local.variable_name);
+		if (rv)
+			return rv;
+	}
 
 	data = kmalloc(setvariable_local.data_size, GFP_KERNEL);
 	if (!data) {
-- 
1.9.1