diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index ca0eef7d3852b56c55641b30de5c87a3c80523d2..f03b3af2fb79295c942480a641f75cbe0273f274 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -579,6 +579,12 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev,
 	}
 
 	stime = mul_u64_u64_div_u64(stime, rtime, stime + utime);
+	/*
+	 * Because mul_u64_u64_div_u64() can approximate on some
+	 * achitectures; enforce the constraint that: a*b/(b+c) <= a.
+	 */
+	if (unlikely(stime > rtime))
+		stime = rtime;
 
 update:
 	/*