From 8629ca8e378bf28312de1674d3a610b75e35fb18 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 18 Apr 2012 16:11:23 +0000 Subject: [PATCH] net ax25: Reorder ax25_exit to remove races. [ Upstream commit 3adadc08cc1e2cbcc15a640d639297ef5fcb17f5 ] While reviewing the sysctl code in ax25 I spotted races in ax25_exit where it is possible to receive notifications and packets after already freeing up some of the data structures needed to process those notifications and updates. Call unregister_netdevice_notifier early so that the rest of the cleanup code does not need to deal with network devices. This takes advantage of my recent enhancement to unregister_netdevice_notifier to send unregister notifications of all network devices that are current registered. Move the unregistration for packet types, socket types and protocol types before we cleanup any of the ax25 data structures to remove the possibilities of other races. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ax25/af_ax25.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index e7c69f4619ec..b04a6ef4da94 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -2006,16 +2006,17 @@ static void __exit ax25_exit(void) proc_net_remove(&init_net, "ax25_route"); proc_net_remove(&init_net, "ax25"); proc_net_remove(&init_net, "ax25_calls"); - ax25_rt_free(); - ax25_uid_free(); - ax25_dev_free(); - ax25_unregister_sysctl(); unregister_netdevice_notifier(&ax25_dev_notifier); + ax25_unregister_sysctl(); dev_remove_pack(&ax25_packet_type); sock_unregister(PF_AX25); proto_unregister(&ax25_proto); + + ax25_rt_free(); + ax25_uid_free(); + ax25_dev_free(); } module_exit(ax25_exit); -- 2.39.2