tipc: fix deadlock during socket release

A deadlock might occur if name table is withdrawn in socket release
routine, and while packets are still being received from bearer.

       CPU0                       CPU1
T0:   recv_msg()               release()
T1:   tipc_recv_msg()          tipc_withdraw()
T2:   [grab node lock]         [grab port lock]
T3:   tipc_link_wakeup_ports() tipc_nametbl_withdraw()
T4:   [grab port lock]*        named_cluster_distribute()
T5:   wakeupdispatch()         tipc_link_send()
T6:                            [grab node lock]*

The opposite order of holding port lock and node lock on above two
different paths may result in a deadlock. If socket lock instead of
port lock is used to protect port instance in tipc_withdraw(), the
reverse order of holding port lock and node lock will be eliminated,
as a result, the deadlock is killed as well.

Reported-by: Lars Everbrand <lars.everbrand@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/tipc/port.h b/net/tipc/port.h
index 912253597343..34f12bd4074e 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -116,7 +116,7 @@ int tipc_reject_msg(struct sk_buff *buf, u32 err);
 
 void tipc_acknowledge(u32 port_ref, u32 ack);
 
-int tipc_deleteport(u32 portref);
+int tipc_deleteport(struct tipc_port *p_ptr);
 
 int tipc_portimportance(u32 portref, unsigned int *importance);
 int tipc_set_portimportance(u32 portref, unsigned int importance);
@@ -127,9 +127,9 @@ int tipc_set_portunreliable(u32 portref, unsigned int isunreliable);
 int tipc_portunreturnable(u32 portref, unsigned int *isunreturnable);
 int tipc_set_portunreturnable(u32 portref, unsigned int isunreturnable);
 
-int tipc_publish(u32 portref, unsigned int scope,
+int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
                  struct tipc_name_seq const *name_seq);
-int tipc_withdraw(u32 portref, unsigned int scope,
+int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
                   struct tipc_name_seq const *name_seq);
 
 int tipc_connect(u32 portref, struct tipc_portid const *port);