route: Fix caught BUG_ON during rt_secret_rebuild_oneshot()

[ 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@openvz.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 6 insertions, 10 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index d62b05d33384..555d27873e03 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -922,10 +922,8 @@ static void rt_secret_rebuild_oneshot(struct net *net)
 {
         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();
 }