From: Patrick McHardy <kaber@trash.net>
Date: Wed, 18 Jul 2007 09:48:43 +0000 (-0700)
Subject: gen estimator timer unload race
X-Git-Tag: v2.6.22.2~75
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e9d3cf88b10374bc7a863f4ad9906245d29d2b3;p=thirdparty%2Fkernel%2Fstable.git

gen estimator timer unload race

[NET]: Fix gen_estimator timer removal race

As noticed by Jarek Poplawski <jarkao2@o2.pl>, the timer removal in
gen_kill_estimator races with the timer function rearming the timer.

Check whether the timer list is empty before rearming the timer
in the timer function to fix this.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/net/core/gen_estimator.c b/net/core/gen_estimator.c
index 17daf4c9f7938..cc84d8d8a3c7d 100644
--- a/net/core/gen_estimator.c
+++ b/net/core/gen_estimator.c
@@ -128,7 +128,8 @@ static void est_timer(unsigned long arg)
 		spin_unlock(e->stats_lock);
 	}
 
-	mod_timer(&elist[idx].timer, jiffies + ((HZ<<idx)/4));
+	if (elist[idx].list != NULL)
+		mod_timer(&elist[idx].timer, jiffies + ((HZ<<idx)/4));
 	read_unlock(&est_lock);
 }