1 files changed, 20 insertions, 11 deletions

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index db1d65963a57..3ac7295306dc 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -283,6 +283,17 @@ static __init int init_posix_timers(void)
 }
 __initcall(init_posix_timers);
 
+/*
+ * The siginfo si_overrun field and the return value of timer_getoverrun(2)
+ * are of type int. Clamp the overrun value to INT_MAX
+ */
+static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
+{
+	s64 sum = timr->it_overrun_last + (s64)baseval;
+
+	return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
+}
+
 static void common_hrtimer_rearm(struct k_itimer *timr)
 {
 	struct hrtimer *timer = &timr->it.real.timer;
@@ -290,9 +301,8 @@ static void common_hrtimer_rearm(struct k_itimer *timr)
 	if (!timr->it_interval)
 		return;
 
-	timr->it_overrun += (unsigned int) hrtimer_forward(timer,
-						timer->base->get_time(),
-						timr->it_interval);
+	timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(),
+					    timr->it_interval);
 	hrtimer_restart(timer);
 }
 
@@ -321,10 +331,10 @@ void posixtimer_rearm(struct siginfo *info)
 
 		timr->it_active = 1;
 		timr->it_overrun_last = timr->it_overrun;
-		timr->it_overrun = -1;
+		timr->it_overrun = -1LL;
 		++timr->it_requeue_pending;
 
-		info->si_overrun += timr->it_overrun_last;
+		info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
 	}
 
 	unlock_timer(timr, flags);
@@ -418,9 +428,8 @@ static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
 					now = ktime_add(now, kj);
 			}
 #endif
-			timr->it_overrun += (unsigned int)
-				hrtimer_forward(timer, now,
-						timr->it_interval);
+			timr->it_overrun += hrtimer_forward(timer, now,
+							    timr->it_interval);
 			ret = HRTIMER_RESTART;
 			++timr->it_requeue_pending;
 			timr->it_active = 1;
@@ -524,7 +533,7 @@ static int do_timer_create(clockid_t which_clock, struct sigevent *event,
 	new_timer->it_id = (timer_t) new_timer_id;
 	new_timer->it_clock = which_clock;
 	new_timer->kclock = kc;
-	new_timer->it_overrun = -1;
+	new_timer->it_overrun = -1LL;
 
 	if (event) {
 		rcu_read_lock();
@@ -702,7 +711,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
 	 * expiry time forward by intervals, so expiry is > now.
 	 */
 	if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
-		timr->it_overrun += (int)kc->timer_forward(timr, now);
+		timr->it_overrun += kc->timer_forward(timr, now);
 
 	remaining = kc->timer_remaining(timr, now);
 	/* Return 0 only, when the timer is expired and not pending */
@@ -791,7 +800,7 @@ SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
 	if (!timr)
 		return -EINVAL;
 
-	overrun = timr->it_overrun_last;
+	overrun = timer_overrun_to_int(timr, 0);
 	unlock_timer(timr, flags);
 
 	return overrun;