From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> [ Upstream commit 6fec64e1c92d5c715c6d0f50786daa7708266bde ] The posix timer ti_overrun handling is broken because the forwarding functions can return a huge number of overruns which does not fit in an int. As a consequence timer_getoverrun(2) and siginfo::si_overrun can turn into random number generators. As a first step to address that let the timer_forward() callbacks return the full 64 bit value. Cast it to (int) temporarily until k_itimer::ti_overrun is converted to 64bit and the conversion to user space visible values is sanitized. Reported-by: Team OWL337 <icytxw@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Acked-by: John Stultz <john.stultz@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx> Link: https://lkml.kernel.org/r/20180626132704.922098090@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- kernel/time/alarmtimer.c | 4 ++-- kernel/time/posix-timers.c | 6 +++--- kernel/time/posix-timers.h | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 481bb6ca6ca0..fa5de5e8de61 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -581,11 +581,11 @@ static void alarm_timer_rearm(struct k_itimer *timr) * @timr: Pointer to the posixtimer data struct * @now: Current time to forward the timer against */ -static int alarm_timer_forward(struct k_itimer *timr, ktime_t now) +static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now) { struct alarm *alarm = &timr->it.alarm.alarmtimer; - return (int) alarm_forward(alarm, timr->it_interval, now); + return alarm_forward(alarm, timr->it_interval, now); } /** diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 708992708332..fb0935612d4e 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -645,11 +645,11 @@ static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now) return __hrtimer_expires_remaining_adjusted(timer, now); } -static int common_hrtimer_forward(struct k_itimer *timr, ktime_t now) +static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now) { struct hrtimer *timer = &timr->it.real.timer; - return (int)hrtimer_forward(timer, now, timr->it_interval); + return hrtimer_forward(timer, now, timr->it_interval); } /* @@ -702,7 +702,7 @@ 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 += kc->timer_forward(timr, now); + timr->it_overrun += (int)kc->timer_forward(timr, now); remaining = kc->timer_remaining(timr, now); /* Return 0 only, when the timer is expired and not pending */ diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h index 151e28f5bf30..ddb21145211a 100644 --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -19,7 +19,7 @@ struct k_clock { void (*timer_get)(struct k_itimer *timr, struct itimerspec64 *cur_setting); void (*timer_rearm)(struct k_itimer *timr); - int (*timer_forward)(struct k_itimer *timr, ktime_t now); + s64 (*timer_forward)(struct k_itimer *timr, ktime_t now); ktime_t (*timer_remaining)(struct k_itimer *timr, ktime_t now); int (*timer_try_to_cancel)(struct k_itimer *timr); void (*timer_arm)(struct k_itimer *timr, ktime_t expires, -- 2.17.1
