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Diffstat (limited to 'kernel/time/alarmtimer.c')
-rw-r--r--kernel/time/alarmtimer.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 5cb5b0008d97..ee2f4202d82a 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -387,7 +387,7 @@ void alarm_start_relative(struct alarm *alarm, ktime_t start)
{
struct alarm_base *base = &alarm_bases[alarm->type];
- start = ktime_add(start, base->gettime());
+ start = ktime_add_safe(start, base->gettime());
alarm_start(alarm, start);
}
EXPORT_SYMBOL_GPL(alarm_start_relative);
@@ -475,7 +475,7 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
overrun++;
}
- alarm->node.expires = ktime_add(alarm->node.expires, interval);
+ alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
return overrun;
}
EXPORT_SYMBOL_GPL(alarm_forward);
@@ -660,13 +660,21 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
/* start the timer */
timr->it.alarm.interval = timespec64_to_ktime(new_setting->it_interval);
+
+ /*
+ * Rate limit to the tick as a hot fix to prevent DOS. Will be
+ * mopped up later.
+ */
+ if (timr->it.alarm.interval < TICK_NSEC)
+ timr->it.alarm.interval = TICK_NSEC;
+
exp = timespec64_to_ktime(new_setting->it_value);
/* Convert (if necessary) to absolute time */
if (flags != TIMER_ABSTIME) {
ktime_t now;
now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
- exp = ktime_add(now, exp);
+ exp = ktime_add_safe(now, exp);
}
alarm_start(&timr->it.alarm.alarmtimer, exp);