Commit 431e2bcc authored Jul 26, 2011 by Thomas Gleixner Committed by Linus Torvalds Jul 26, 2011

rtc: limit frequency



Due to the hrtimer self rearming mode a user can DoS the machine simply
because it's starved by hrtimer events.

The RTC hrtimer is self rearming.  We really need to limit the frequency
to something sensible.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ben Greear <greearb@candelatech.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 2c4f57d1

drivers/rtc/interface.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -688,7 +688,7 @@ int rtc_irq_set_freq(struct rtc_device rtc, struct rtc_task task, int freq)
		int err = 0;
		unsigned long flags;

		if (freq <= 0)
		if (freq <= 0 \|\| freq > 5000)
		return -EINVAL;

		spin_lock_irqsave(&rtc->irq_task_lock, flags);