4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 15ef70e286176165d28b0b8a969b422561a68dfc ]
lock_sock() must be used in process context to be race-free with other lock_sock() callers, for example, tipc_release(). Otherwise using the spinlock directly can't serialize a parallel tipc_release().
As it is blocking, we have to hold the sock refcnt before rhashtable_walk_stop() and release it after rhashtable_walk_start().
Fixes: 07f6c4bc048a ("tipc: convert tipc reference table to use generic rhashtable") Reported-by: Dmitry Vyukov dvyukov@google.com Cc: Ying Xue ying.xue@windriver.com Cc: Jon Maloy jon.maloy@ericsson.com Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tipc/socket.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2281,11 +2281,15 @@ void tipc_sk_reinit(struct net *net) goto walk_stop;
while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) { - spin_lock_bh(&tsk->sk.sk_lock.slock); + sock_hold(&tsk->sk); + rhashtable_walk_stop(&iter); + lock_sock(&tsk->sk); msg = &tsk->phdr; msg_set_prevnode(msg, tn->own_addr); msg_set_orignode(msg, tn->own_addr); - spin_unlock_bh(&tsk->sk.sk_lock.slock); + release_sock(&tsk->sk); + rhashtable_walk_start(&iter); + sock_put(&tsk->sk); } walk_stop: rhashtable_walk_stop(&iter);