[PATCH] hrtimers: prevent possible itimer DoS

Fix potential setitimer DoS with high-res timers by pushing itimer rearm
processing to process context.

[Fixes from: Ingo Molnar <mingo@elte.hu>]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner
2007-02-16 01:28:12 -08:00
committed by Linus Torvalds
parent 54cdfdb47f
commit 8bfd9a7a22
2 changed files with 47 additions and 25 deletions

View File

@@ -135,11 +135,6 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);
if (sig->it_real_incr.tv64 != 0) {
hrtimer_forward(timer, hrtimer_cb_get_time(timer),
sig->it_real_incr);
return HRTIMER_RESTART;
}
return HRTIMER_NORESTART;
}
@@ -231,11 +226,14 @@ again:
spin_unlock_irq(&tsk->sighand->siglock);
goto again;
}
tsk->signal->it_real_incr =
timeval_to_ktime(value->it_interval);
expires = timeval_to_ktime(value->it_value);
if (expires.tv64 != 0)
if (expires.tv64 != 0) {
tsk->signal->it_real_incr =
timeval_to_ktime(value->it_interval);
hrtimer_start(timer, expires, HRTIMER_MODE_REL);
} else
tsk->signal->it_real_incr.tv64 = 0;
spin_unlock_irq(&tsk->sighand->siglock);
break;
case ITIMER_VIRTUAL: