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A deadlock might occur if name table is withdrawn in socket release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>
diff --git a/net/tipc/port.c b/net/tipc/port.c
index c081a76..d43f318 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -251,18 +251,15 @@
return p_ptr;
}
-int tipc_deleteport(u32 ref)
+int tipc_deleteport(struct tipc_port *p_ptr)
{
- struct tipc_port *p_ptr;
struct sk_buff *buf = NULL;
- tipc_withdraw(ref, 0, NULL);
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
- return -EINVAL;
+ tipc_withdraw(p_ptr, 0, NULL);
- tipc_ref_discard(ref);
- tipc_port_unlock(p_ptr);
+ spin_lock_bh(p_ptr->lock);
+ tipc_ref_discard(p_ptr->ref);
+ spin_unlock_bh(p_ptr->lock);
k_cancel_timer(&p_ptr->timer);
if (p_ptr->connected) {
@@ -704,47 +701,36 @@
}
-int tipc_publish(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
+int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
+ struct tipc_name_seq const *seq)
{
- struct tipc_port *p_ptr;
struct publication *publ;
u32 key;
- int res = -EINVAL;
-
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
- return -EINVAL;
if (p_ptr->connected)
- goto exit;
- key = ref + p_ptr->pub_count + 1;
- if (key == ref) {
- res = -EADDRINUSE;
- goto exit;
- }
+ return -EINVAL;
+ key = p_ptr->ref + p_ptr->pub_count + 1;
+ if (key == p_ptr->ref)
+ return -EADDRINUSE;
+
publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper,
scope, p_ptr->ref, key);
if (publ) {
list_add(&publ->pport_list, &p_ptr->publications);
p_ptr->pub_count++;
p_ptr->published = 1;
- res = 0;
+ return 0;
}
-exit:
- tipc_port_unlock(p_ptr);
- return res;
+ return -EINVAL;
}
-int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
+int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
+ struct tipc_name_seq const *seq)
{
- struct tipc_port *p_ptr;
struct publication *publ;
struct publication *tpubl;
int res = -EINVAL;
- p_ptr = tipc_port_lock(ref);
- if (!p_ptr)
- return -EINVAL;
if (!seq) {
list_for_each_entry_safe(publ, tpubl,
&p_ptr->publications, pport_list) {
@@ -771,7 +757,6 @@
}
if (list_empty(&p_ptr->publications))
p_ptr->published = 0;
- tipc_port_unlock(p_ptr);
return res;
}