Commit 53cc2820 authored Jul 22, 2011 by Thomas Gleixner Committed by John Stultz Jul 26, 2011

rtc: Handle errors correctly in rtc_irq_set_state()



In rtc_irq_set_state, the code checks the correctness of the parameters,
but then goes on to unconditionally arms/disarms the hrtimer. Thus a
random task might arm/disarm rtc timer and surprise the real owner by
either generating events or by stopping them.

Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

parent ef68c8f8

drivers/rtc/interface.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -656,6 +656,8 @@ int rtc_irq_set_state(struct rtc_device rtc, struct rtc_task task, int enabled
		err = -EBUSY;
		if (rtc->irq_task != task)
		err = -EACCES;
		if (err)
		goto out;

		if (enabled) {
		ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
		@@ -664,6 +666,7 @@ int rtc_irq_set_state(struct rtc_device rtc, struct rtc_task task, int enabled
		hrtimer_cancel(&rtc->pie_timer);
		}
		rtc->pie_enabled = enabled;
		out:
		spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

		return err;

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