Commit 84602761 authored by Ying Xue's avatar Ying Xue Committed by David S. Miller

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A deadlock might occur if name table is withdrawn in socket release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: default avatarLars Everbrand <lars.everbrand@ericsson.com>
Reviewed-by: default avatarErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: default avatarYing Xue <ying.xue@windriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8eb9bff0
......@@ -251,18 +251,15 @@ struct tipc_port *tipc_createport(struct sock *sk,
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_set_portimportance(u32 ref, unsigned int imp)
}
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)
if (p_ptr->connected)
return -EINVAL;
key = p_ptr->ref + p_ptr->pub_count + 1;
if (key == p_ptr->ref)
return -EADDRINUSE;
if (p_ptr->connected)
goto exit;
key = ref + p_ptr->pub_count + 1;
if (key == ref) {
res = -EADDRINUSE;
goto exit;
}
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 @@ int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq)
}
if (list_empty(&p_ptr->publications))
p_ptr->published = 0;
tipc_port_unlock(p_ptr);
return res;
}
......
......@@ -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);
......
......@@ -354,7 +354,7 @@ static int release(struct socket *sock)
* Delete TIPC port; this ensures no more messages are queued
* (also disconnects an active connection & sends a 'FIN-' to peer)
*/
res = tipc_deleteport(tport->ref);
res = tipc_deleteport(tport);
/* Discard any remaining (connection-based) messages in receive queue */
__skb_queue_purge(&sk->sk_receive_queue);
......@@ -386,30 +386,46 @@ static int release(struct socket *sock)
*/
static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
{
struct sock *sk = sock->sk;
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
u32 portref = tipc_sk_port(sock->sk)->ref;
struct tipc_port *tport = tipc_sk_port(sock->sk);
int res = -EINVAL;
if (unlikely(!uaddr_len))
return tipc_withdraw(portref, 0, NULL);
lock_sock(sk);
if (unlikely(!uaddr_len)) {
res = tipc_withdraw(tport, 0, NULL);
goto exit;
}
if (uaddr_len < sizeof(struct sockaddr_tipc))
return -EINVAL;
if (addr->family != AF_TIPC)
return -EAFNOSUPPORT;
if (uaddr_len < sizeof(struct sockaddr_tipc)) {
res = -EINVAL;
goto exit;
}
if (addr->family != AF_TIPC) {
res = -EAFNOSUPPORT;
goto exit;
}
if (addr->addrtype == TIPC_ADDR_NAME)
addr->addr.nameseq.upper = addr->addr.nameseq.lower;
else if (addr->addrtype != TIPC_ADDR_NAMESEQ)
return -EAFNOSUPPORT;
else if (addr->addrtype != TIPC_ADDR_NAMESEQ) {
res = -EAFNOSUPPORT;
goto exit;
}
if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) &&
(addr->addr.nameseq.type != TIPC_TOP_SRV) &&
(addr->addr.nameseq.type != TIPC_CFG_SRV))
return -EACCES;
(addr->addr.nameseq.type != TIPC_CFG_SRV)) {
res = -EACCES;
goto exit;
}
return (addr->scope > 0) ?
tipc_publish(portref, addr->scope, &addr->addr.nameseq) :
tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq);
res = (addr->scope > 0) ?
tipc_publish(tport, addr->scope, &addr->addr.nameseq) :
tipc_withdraw(tport, -addr->scope, &addr->addr.nameseq);
exit:
release_sock(sk);
return res;
}
/**
......
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