bridge: kernel panic when unloading bridge module
There is a race condition when unloading bridge and netfilter.
The problem happens if __fake_rtable is in use by a skb
coming in, while someone starts to unload bridge.ko.
br_netfilter_fini() is called at the beginning of unload
in br_deinit() while skbs still are being forwarded and
transferred to local ip stack. Thus there is a possibility
of the __fake_rtable pointer not being removed in a skb that
goes up to ip stack. This results in a kernel panic, as
ip_rcv() calls the input-function of __fake_rtable, which
is NULL.
Moving the call of br_netfilter_fini() to the end of
br_deinit() solves the problem.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Stephen Hemminger <stephen.hemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br.c b/net/bridge/br.c
index a901828..8f3c58e 100644
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -76,7 +76,6 @@
rcu_assign_pointer(br_stp_sap->rcv_func, NULL);
br_netlink_fini();
- br_netfilter_fini();
unregister_netdevice_notifier(&br_device_notifier);
brioctl_set(NULL);
@@ -84,6 +83,7 @@
synchronize_net();
+ br_netfilter_fini();
llc_sap_put(br_stp_sap);
br_fdb_get_hook = NULL;
br_fdb_put_hook = NULL;