[PATCH 4.19 32/32] tipc: fix modprobe tipc failed after switch order of device registration

Greg Kroah-Hartman
2019-06-03T09:10:49Z

From: Junwei Hu <hujunwei4@huawei.com>

commit 526f5b851a96566803ee4bee60d0a34df56c77f8 upstream.

Error message printed:
modprobe: ERROR: could not insert 'tipc': Address family not
supported by protocol.
when modprobe tipc after the following patch: switch order of
device registration, commit 7e27e8d6130c
("tipc: switch order of device registration to fix a crash")

Because sock_create_kern(net, AF_TIPC, ...) called by
tipc_topsrv_create_listener() in the initialization process
of tipc_init_net(), so tipc_socket_init() must be execute before that.
Meanwhile, tipc_net_id need to be initialized when sock_create()
called, and tipc_socket_init() is no need to be called for each namespace.

I add a variable tipc_topsrv_net_ops, and split the
register_pernet_subsys() of tipc into two parts, and split
tipc_socket_init() with initialization of pernet params.

By the way, I fixed resources rollback error when tipc_bcast_init()
failed in tipc_init_net().

Fixes: 7e27e8d6130c ("tipc: switch order of device registration to fix a crash")
Signed-off-by: Junwei Hu <hujunwei4@huawei.com>
Reported-by: Wang Wang <wangwang2@huawei.com>
Reported-by: syzbot+1e8114b61079bfe9cbc5@syzkaller.appspotmail.com
Reviewed-by: Kang Zhou <zhoukang7@huawei.com>
Reviewed-by: Suanming Mou <mousuanming@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/tipc/core.c | 18 ++++++++++++------
net/tipc/subscr.h | 5 +++--
net/tipc/topsrv.c | 14 ++++++++++++--
3 files changed, 27 insertions(+), 10 deletions(-)

--- a/net/tipc/core.c
+++ b/net/tipc/core.c
@@ -75,9 +75,6 @@ static int __net_init tipc_init_net(stru
goto out_nametbl;

INIT_LIST_HEAD(&tn->dist_queue);
- err = tipc_topsrv_start(net);
- if (err)
- goto out_subscr;

err = tipc_bcast_init(net);
if (err)
@@ -86,8 +83,6 @@ static int __net_init tipc_init_net(stru
return 0;

out_bclink:
- tipc_bcast_stop(net);
-out_subscr:
tipc_nametbl_stop(net);
out_nametbl:
tipc_sk_rht_destroy(net);
@@ -97,7 +92,6 @@ out_sk_rht:

static void __net_exit tipc_exit_net(struct net *net)
{
- tipc_topsrv_stop(net);
tipc_net_stop(net);
tipc_bcast_stop(net);
tipc_nametbl_stop(net);
@@ -111,6 +105,11 @@ static struct pernet_operations tipc_net
.size = sizeof(struct tipc_net),
};

+static struct pernet_operations tipc_topsrv_net_ops = {
+ .init = tipc_topsrv_init_net,
+ .exit = tipc_topsrv_exit_net,
+};
+
static int __init tipc_init(void)
{
int err;
@@ -141,6 +140,10 @@ static int __init tipc_init(void)
if (err)
goto out_socket;

+ err = register_pernet_subsys(&tipc_topsrv_net_ops);
+ if (err)
+ goto out_pernet_topsrv;
+
err = tipc_bearer_setup();
if (err)
goto out_bearer;
@@ -148,6 +151,8 @@ static int __init tipc_init(void)
pr_info("Started in single node mode\n");
return 0;
out_bearer:
+ unregister_pernet_subsys(&tipc_topsrv_net_ops);
+out_pernet_topsrv:
tipc_socket_stop();
out_socket:
unregister_pernet_subsys(&tipc_net_ops);
@@ -165,6 +170,7 @@ out_netlink:
static void __exit tipc_exit(void)
{
tipc_bearer_cleanup();
+ unregister_pernet_subsys(&tipc_topsrv_net_ops);
tipc_socket_stop();
unregister_pernet_subsys(&tipc_net_ops);
tipc_netlink_stop();
--- a/net/tipc/subscr.h
+++ b/net/tipc/subscr.h
@@ -77,8 +77,9 @@ void tipc_sub_report_overlap(struct tipc
u32 found_lower, u32 found_upper,
u32 event, u32 port, u32 node,
u32 scope, int must);
-int tipc_topsrv_start(struct net *net);
-void tipc_topsrv_stop(struct net *net);
+
+int __net_init tipc_topsrv_init_net(struct net *net);
+void __net_exit tipc_topsrv_exit_net(struct net *net);

void tipc_sub_put(struct tipc_subscription *subscription);
void tipc_sub_get(struct tipc_subscription *subscription);
--- a/net/tipc/topsrv.c
+++ b/net/tipc/topsrv.c
@@ -643,7 +643,7 @@ static void tipc_topsrv_work_stop(struct
destroy_workqueue(s->send_wq);
}

-int tipc_topsrv_start(struct net *net)
+static int tipc_topsrv_start(struct net *net)
{
struct tipc_net *tn = tipc_net(net);
const char name[] = "topology_server";
@@ -677,7 +677,7 @@ int tipc_topsrv_start(struct net *net)
return ret;
}

-void tipc_topsrv_stop(struct net *net)
+static void tipc_topsrv_stop(struct net *net)
{
struct tipc_topsrv *srv = tipc_topsrv(net);
struct socket *lsock = srv->listener;
@@ -702,3 +702,13 @@ void tipc_topsrv_stop(struct net *net)
idr_destroy(&srv->conn_idr);
kfree(srv);
}
+
+int __net_init tipc_topsrv_init_net(struct net *net)
+{
+ return tipc_topsrv_start(net);
+}
+
+void __net_exit tipc_topsrv_exit_net(struct net *net)
+{
+ tipc_topsrv_stop(net);
+}