Commit: ec054bbddbd0841174f4d5c3a4685eca9f9a9f93 - linux_3.x_apsh4a0a (git)

linux-3.0.x for AP-SH4A-0A Board

Commit MetaInfo

• Revisão: ec054bbddbd0841174f4d5c3a4685eca9f9a9f93 (tree)
• Hora: 2011-08-05 13:58:32
• Autor: Thomas Gleixner <tglx@linu...>
• Commiter: Greg Kroah-Hartman

Mensagem de Log

rtc: limit frequency

commit 431e2bcc371016824f419baa745f82388258f3ee upstream.

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 <[e-mail]>
Cc: John Stultz <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Ben Greear <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Mudança Sumário

• modified: drivers/rtc/interface.c

Diff

--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -708,7 +708,7 @@ 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;
 retry:
 	spin_lock_irqsave(&rtc->irq_task_lock, flags);