diff --git a/sys/dev/powermng/powernow/powernow.c b/sys/dev/powermng/powernow/powernow.c
--- a/sys/dev/powermng/powernow/powernow.c
+++ b/sys/dev/powermng/powernow/powernow.c
@@ -363,7 +363,7 @@
 		return 2;
 	/* Extended CPUID signature value */
 	do_cpuid(0x80000001, regs);
-	cstate = kmalloc(sizeof(struct k8pnow_cpu_state), M_DEVBUF, M_WAITOK);
+	cstate = kmalloc(sizeof(struct k8pnow_cpu_state), M_DEVBUF, M_WAITOK | M_ZERO);
 	cstate->n_states = 0;
 
 	status = rdmsr(MSR_AMDK7_FIDVID_STATUS);