diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-02-18 14:39:18 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-18 17:35:51 +0100 |
| commit | 7716682cc58e305e22207d5bb315f26af6b1e243 (patch) | |
| tree | bd3b7c897a192192bf0312cca7f4cd0e5f39da5d /include/net/inet_connection_sock.h | |
| parent | route: check and remove route cache when we get route (diff) | |
| download | linux-7716682cc58e305e22207d5bb315f26af6b1e243.tar.xz linux-7716682cc58e305e22207d5bb315f26af6b1e243.zip | |
tcp/dccp: fix another race at listener dismantle
Ilya reported following lockdep splat:
kernel: =========================
kernel: [ BUG: held lock freed! ]
kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted
kernel: -------------------------
kernel: swapper/5/0 is freeing memory
ffff880035c9d200-ffff880035c9dbff, with a lock still held there!
kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0
kernel: 4 locks held by swapper/5/0:
kernel: #0: (rcu_read_lock){......}, at: [<ffffffff8169ef6b>]
netif_receive_skb_internal+0x4b/0x1f0
kernel: #1: (rcu_read_lock){......}, at: [<ffffffff816e977f>]
ip_local_deliver_finish+0x3f/0x380
kernel: #2: (slock-AF_INET){+.-...}, at: [<ffffffff81685ffb>]
sk_clone_lock+0x19b/0x440
kernel: #3: (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0
To properly fix this issue, inet_csk_reqsk_queue_add() needs
to return to its callers if the child as been queued
into accept queue.
We also need to make sure listener is still there before
calling sk->sk_data_ready(), by holding a reference on it,
since the reference carried by the child can disappear as
soon as the child is put on accept queue.
Reported-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: ebb516af60e1 ("tcp/dccp: fix race at listener dismantle phase")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/inet_connection_sock.h')
| -rw-r--r-- | include/net/inet_connection_sock.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 481fe1c9044c..49dcad4fe99e 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -270,8 +270,9 @@ struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, struct sock *newsk, const struct request_sock *req); -void inet_csk_reqsk_queue_add(struct sock *sk, struct request_sock *req, - struct sock *child); +struct sock *inet_csk_reqsk_queue_add(struct sock *sk, + struct request_sock *req, + struct sock *child); void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, unsigned long timeout); struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, |