From: Greg KH on
2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Vitaliy Gusev <vgusev(a)openvz.org>

[ Upstream commit 858a18a6a2f74e8f0e5b2e9671d4b74694aba708 ]

route: Fix caught BUG_ON during rt_secret_rebuild_oneshot()

Call rt_secret_rebuild can cause BUG_ON(timer_pending(&net->ipv4.rt_secret_timer)) in
add_timer as there is not any synchronization for call rt_secret_rebuild_oneshot()
for the same net namespace.

Also this issue affects to rt_secret_reschedule().

Thus use mod_timer enstead.

Signed-off-by: Vitaliy Gusev <vgusev(a)openvz.org>
Acked-by: Neil Horman <nhorman(a)tuxdriver.com>
Signed-off-by: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
net/ipv4/route.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -922,10 +922,8 @@ static void rt_secret_rebuild_oneshot(st
{
del_timer_sync(&net->ipv4.rt_secret_timer);
rt_cache_invalidate(net);
- if (ip_rt_secret_interval) {
- net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
- add_timer(&net->ipv4.rt_secret_timer);
- }
+ if (ip_rt_secret_interval)
+ mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
}

static void rt_emergency_hash_rebuild(struct net *net)
@@ -3072,22 +3070,20 @@ static void rt_secret_reschedule(int old
rtnl_lock();
for_each_net(net) {
int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+ long time;

if (!new)
continue;

if (deleted) {
- long time = net->ipv4.rt_secret_timer.expires - jiffies;
+ time = net->ipv4.rt_secret_timer.expires - jiffies;

if (time <= 0 || (time += diff) <= 0)
time = 0;
-
- net->ipv4.rt_secret_timer.expires = time;
} else
- net->ipv4.rt_secret_timer.expires = new;
+ time = new;

- net->ipv4.rt_secret_timer.expires += jiffies;
- add_timer(&net->ipv4.rt_secret_timer);
+ mod_timer(&net->ipv4.rt_secret_timer, jiffies + time);
}
rtnl_unlock();
}


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