[NETNS]: The ip6_fib_timer can work with garbage on net namespace stop.
The del_timer() function doesn't guarantee, that the timer callback
is not active by the time it exits.
Thus, the fib6_net_exit() may kfree() all the data, that is required
by the fib6_run_gc(). The race window is tiny, but slab poisoning can
trigger this bug.
Using del_timer_sync() will cure this.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 50f3f8f..1ee4fa1 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1543,7 +1543,7 @@
static void fib6_net_exit(struct net *net)
{
rt6_ifdown(net, NULL);
- del_timer(net->ipv6.ip6_fib_timer);
+ del_timer_sync(net->ipv6.ip6_fib_timer);
kfree(net->ipv6.ip6_fib_timer);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
kfree(net->ipv6.fib6_local_tbl);
