diff options
| author | Guillaume Nault <gnault@redhat.com> | 2019-03-08 22:09:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 08:44:30 +0100 |
| commit | 191aa19ab8c1459c11a5c541801f17e01dda17de (patch) | |
| tree | 28ceaef38926abd07158a92fda17597303b36b20 | |
| parent | d31b540d63b19f60ae34195aab5644862ea0a683 (diff) | |
tcp: handle inet_csk_reqsk_queue_add() failures
[ Upstream commit 9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af ]
Commit 7716682cc58e ("tcp/dccp: fix another race at listener
dismantle") let inet_csk_reqsk_queue_add() fail, and adjusted
{tcp,dccp}_check_req() accordingly. However, TFO and syncookies
weren't modified, thus leaking allocated resources on error.
Contrary to tcp_check_req(), in both syncookies and TFO cases,
we need to drop the request socket. Also, since the child socket is
created with inet_csk_clone_lock(), we have to unlock it and drop an
extra reference (->sk_refcount is initially set to 2 and
inet_csk_reqsk_queue_add() drops only one ref).
For TFO, we also need to revert the work done by tcp_try_fastopen()
(with reqsk_fastopen_remove()).
Fixes: 7716682cc58e ("tcp/dccp: fix another race at listener dismantle")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/syncookies.c | 7 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 8 |
2 files changed, 13 insertions, 2 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index c22a74374a9c..f3d3ac5c23d5 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -228,7 +228,12 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, if (child) { atomic_set(&req->rsk_refcnt, 1); sock_rps_save_rxhash(child, skb); - inet_csk_reqsk_queue_add(sk, req, child); + if (!inet_csk_reqsk_queue_add(sk, req, child)) { + bh_unlock_sock(child); + sock_put(child); + child = NULL; + reqsk_put(req); + } } else { reqsk_free(req); } diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 1aff93d76f24..561f568e8938 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6409,7 +6409,13 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, af_ops->send_synack(fastopen_sk, dst, &fl, req, &foc, false); /* Add the child socket directly into the accept queue */ - inet_csk_reqsk_queue_add(sk, req, fastopen_sk); + if (!inet_csk_reqsk_queue_add(sk, req, fastopen_sk)) { + reqsk_fastopen_remove(fastopen_sk, req, false); + bh_unlock_sock(fastopen_sk); + sock_put(fastopen_sk); + reqsk_put(req); + goto drop; + } sk->sk_data_ready(sk); bh_unlock_sock(fastopen_sk); sock_put(fastopen_sk); |