path: root/kernel/hrtimer.c
diff options
authorThomas Gleixner <tglx@linutronix.de>2007-03-16 13:38:20 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-03-16 19:25:05 -0700
commit13788ccc41ceea5893f9c747c59bc0b28f2416c2 (patch)
tree34cc13deaf8e7209def55edfad1912f308bf8c0d /kernel/hrtimer.c
parentd8ad7e0b84bde480d295ef1e0381c0c6050f57b3 (diff)
[PATCH] hrtimer: prevent overrun DoS in hrtimer_forward()
hrtimer_forward() does not check for the possible overflow of timer->expires. This can happen on 64 bit machines with large interval values and results currently in an endless loop in the softirq because the expiry value becomes negative and therefor the timer is expired all the time. Check for this condition and set the expiry value to the max. expiry time in the future. The fix should be applied to stable kernel series as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/hrtimer.c')
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index ec4cb9f3e3b7..5e7122d3f46f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -644,6 +644,12 @@ hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
timer->expires = ktime_add(timer->expires, interval);
+ /*
+ * Make sure, that the result did not wrap with a very large
+ * interval.
+ */
+ if (timer->expires.tv64 < 0)
+ timer->expires = ktime_set(KTIME_SEC_MAX, 0);
return orun;