From 7ef43ebaa538e0cc9063cbf84593a05091bcace2 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Mon, 12 May 2008 15:42:28 -0700 Subject: tipc: Fix race condition when creating socket or native port This patch eliminates the (very remote) chance of a crash resulting from a partially initialized socket or native port unexpectedly receiving a message. Now, during the creation of a socket or native port, the underlying generic port's lock is not released until all initialization required to handle incoming messages has been done. Signed-off-by: Allan Stephens Signed-off-by: David S. Miller --- net/tipc/port.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'net/tipc/port.c') diff --git a/net/tipc/port.c b/net/tipc/port.c index 2f5806410c64..757de38fe6af 100644 --- a/net/tipc/port.c +++ b/net/tipc/port.c @@ -211,15 +211,18 @@ exit: } /** - * tipc_createport_raw - create a native TIPC port + * tipc_createport_raw - create a generic TIPC port * - * Returns local port reference + * Returns port reference, or 0 if unable to create it + * + * Note: The newly created port is returned in the locked state. */ u32 tipc_createport_raw(void *usr_handle, u32 (*dispatcher)(struct tipc_port *, struct sk_buff *), void (*wakeup)(struct tipc_port *), - const u32 importance) + const u32 importance, + struct tipc_port **tp_ptr) { struct port *p_ptr; struct tipc_msg *msg; @@ -237,7 +240,6 @@ u32 tipc_createport_raw(void *usr_handle, return 0; } - tipc_port_lock(ref); p_ptr->publ.usr_handle = usr_handle; p_ptr->publ.max_pkt = MAX_PKT_DEFAULT; p_ptr->publ.ref = ref; @@ -262,7 +264,7 @@ u32 tipc_createport_raw(void *usr_handle, INIT_LIST_HEAD(&p_ptr->port_list); list_add_tail(&p_ptr->port_list, &ports); spin_unlock_bh(&tipc_port_list_lock); - tipc_port_unlock(p_ptr); + *tp_ptr = &p_ptr->publ; return ref; } @@ -1053,6 +1055,7 @@ int tipc_createport(u32 user_ref, { struct user_port *up_ptr; struct port *p_ptr; + struct tipc_port *tp_ptr; u32 ref; up_ptr = kmalloc(sizeof(*up_ptr), GFP_ATOMIC); @@ -1060,12 +1063,13 @@ int tipc_createport(u32 user_ref, warn("Port creation failed, no memory\n"); return -ENOMEM; } - ref = tipc_createport_raw(NULL, port_dispatcher, port_wakeup, importance); - p_ptr = tipc_port_lock(ref); - if (!p_ptr) { + ref = tipc_createport_raw(NULL, port_dispatcher, port_wakeup, + importance, &tp_ptr); + if (ref == 0) { kfree(up_ptr); return -ENOMEM; } + p_ptr = (struct port *)tp_ptr; p_ptr->user_port = up_ptr; up_ptr->user_ref = user_ref; -- cgit v1.2.3-58-ga151