From 1cceda7849809a8857fd9f26efe8846506c710e1 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 29 Sep 2016 02:55:44 +0800 Subject: sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock When sctp dumps all the ep->assocs, it needs to lock_sock first, but now it locks sock in rcu_read_lock, and lock_sock may sleep, which would break rcu_read_lock. This patch is to get and hold one sock when traversing the list. After that and get out of rcu_read_lock, lock and dump it. Then it will traverse the list again to get the next one until all sctp socks are dumped. For sctp_diag_dump_one, it fixes this issue by holding asoc and moving cb() out of rcu_read_lock in sctp_transport_lookup_process. Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/sctp/socket.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'net/sctp/socket.c') diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 9fc417a8b476..8ed2d99bde6d 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4469,17 +4469,21 @@ int sctp_transport_lookup_process(int (*cb)(struct sctp_transport *, void *), const union sctp_addr *paddr, void *p) { struct sctp_transport *transport; - int err = 0; + int err = -ENOENT; rcu_read_lock(); transport = sctp_addrs_lookup_transport(net, laddr, paddr); if (!transport || !sctp_transport_hold(transport)) goto out; - err = cb(transport, p); + + sctp_association_hold(transport->asoc); sctp_transport_put(transport); -out: rcu_read_unlock(); + err = cb(transport, p); + sctp_association_put(transport->asoc); + +out: return err; } EXPORT_SYMBOL_GPL(sctp_transport_lookup_process); -- cgit v1.2.3