diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index eb913f80bfb1f6540aaad75d584fc2af2646b95f..865b9648d0d57057fe1af797d67d6faea5345459 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -724,7 +724,7 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
 		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
 
 #ifdef CONFIG_CMDLINE
-	if (l == 0 || (l == 1 && (*p) == 0))
+	if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
 		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #endif /* CONFIG_CMDLINE */