diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index b3b94cd37713..1d815405a3b4 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1352,7 +1352,7 @@ static int cpu_cmd(void)
 	}
 	termch = cpu;
 
-	if (!scanhex(&cpu)) {
+	if (!scanhex(&cpu) || cpu >= num_possible_cpus()) {
 		/* print cpus waiting or in xmon */
 		printf("cpus stopped:");
 		last_cpu = first_cpu = NR_CPUS;
@@ -2774,7 +2774,7 @@ static void dump_pacas(void)
 
 	termch = c;	/* Put c back, it wasn't 'a' */
 
-	if (scanhex(&num))
+	if (scanhex(&num) && num < num_possible_cpus())
 		dump_one_paca(num);
 	else
 		dump_one_paca(xmon_owner);
@@ -2847,7 +2847,7 @@ static void dump_xives(void)
 
 	termch = c;	/* Put c back, it wasn't 'a' */
 
-	if (scanhex(&num))
+	if (scanhex(&num) && num < num_possible_cpus())
 		dump_one_xive(num);
 	else
 		dump_one_xive(xmon_owner);