From cc4b6e7755a8c351d7ddf32b5f2e7f101cea5aa6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 26 Jul 2011 16:08:18 -0700 Subject: rtc: handle errors correctly in rtc_irq_set_state() commit 2c4f57d12df7696d65b0247bfd57fd082a7719e6 upstream. The code checks the correctness of the parameters, but unconditionally arms/disarms the hrtimer. The result is that a random task might arm/disarm rtc timer and surprise the real owner by either generating events or by stopping them. Signed-off-by: Thomas Gleixner Cc: John Stultz Cc: Ingo Molnar Cc: Ben Greear Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/interface.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index df68618..b6bf57f 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -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; -- cgit v1.1