From 84602761ca4495dd409be936dfa93ed20c946684 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Fri, 27 Dec 2013 10:18:28 +0800 Subject: tipc: fix deadlock during socket release A deadlock might occur if name table is withdrawn in socket release routine, and while packets are still being received from bearer.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 Reviewed-by: Erik Hugne Signed-off-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/port.c | 45 +++++++++++++++------------------------------ 1 file changed, 15 insertions(+), 30 deletions(-) (limited to 'net/tipc/port.c') diff --git a/net/tipc/port.c b/net/tipc/port.c index c081a7632302..d43f3182b1d4 100644 --- a/net/tipc/port.c +++ b/net/tipc/port.c @@ -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; } -- cgit v1.2.3-70-g09d2