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authorGuillaume Nault <gnault@redhat.com>2019-03-09 00:09:47 +0300
committerDavid S. Miller <davem@davemloft.net>2019-03-09 03:05:10 +0300
commit9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af (patch)
tree803b92c4735eb270910bc9846273b00e65343729 /net
parent09073525f8b9095931e5a82209b61abc7ce4c9d5 (diff)
downloadlinux-9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af.tar.xz
tcp: handle inet_csk_reqsk_queue_add() failures
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>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/syncookies.c7
-rw-r--r--net/ipv4/tcp_input.c8
2 files changed, 13 insertions, 2 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 606f868d9f3f..e531344611a0 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -216,7 +216,12 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb,
refcount_set(&req->rsk_refcnt, 1);
tcp_sk(child)->tsoffset = tsoff;
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 4eb0c8ca3c60..5def3c48870e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6498,7 +6498,13 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
af_ops->send_synack(fastopen_sk, dst, &fl, req,
&foc, TCP_SYNACK_FASTOPEN);
/* 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);