diff --git a/[refs] b/[refs]
index db43705d4c8c..9b1c72817ff0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c22d4c1885130db9c07f6441ab461208a1ba16b2
+refs/heads/master: a737abd11ac4eb9f4226fa8c9f1d9b5be12a96c1
diff --git a/trunk/arch/x86/kernel/e820.c b/trunk/arch/x86/kernel/e820.c
index 292ebc7fe4d0..66fd5bd78318 100644
--- a/trunk/arch/x86/kernel/e820.c
+++ b/trunk/arch/x86/kernel/e820.c
@@ -1198,6 +1198,9 @@ static int __init parse_memmap_opt(char *p)
 	char *oldp;
 	u64 start_at, mem_size;
 
+	if (!p)
+		return -EINVAL;
+
 	if (!strcmp(p, "exactmap")) {
 #ifdef CONFIG_CRASH_DUMP
 		/*