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authorGuillaume Nault <gnault@redhat.com>2019-03-19 18:05:44 +0300
committerDavid S. Miller <davem@davemloft.net>2019-03-20 00:13:01 +0300
commit9403cf2302588022d06f1878b072d3f6933021f0 (patch)
treed69594772fc7481e9db2f296b0c4ac8fe6d4a591 /net/ipv4/syncookies.c
parent56dc6d6355744b1c890dd09a6627e0c492f83bb9 (diff)
downloadlinux-9403cf2302588022d06f1878b072d3f6933021f0.tar.xz
tcp: free request sock directly upon TFO or syncookies error
Since the request socket is created locally, it'd make more sense to use reqsk_free() instead of reqsk_put() in TFO and syncookies' error path. However, tcp_get_cookie_sock() may set ->rsk_refcnt before freeing the socket; tcp_conn_request() may also have non-null ->rsk_refcnt because of tcp_try_fastopen(). In both cases 'req' hasn't been exposed to the outside world and is safe to free immediately, but that'd trigger the WARN_ON_ONCE in reqsk_free(). Define __reqsk_free() for these situations where we know nobody's referencing the socket, even though ->rsk_refcnt might be non-null. Now we can consolidate the error path of tcp_get_cookie_sock() and tcp_conn_request(). 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/ipv4/syncookies.c')
-rw-r--r--net/ipv4/syncookies.c17
1 files changed, 8 insertions, 9 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index e531344611a0..008545f63667 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -216,16 +216,15 @@ 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);
- 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);
+ if (inet_csk_reqsk_queue_add(sk, req, child))
+ return child;
+
+ bh_unlock_sock(child);
+ sock_put(child);
}
- return child;
+ __reqsk_free(req);
+
+ return NULL;
}
EXPORT_SYMBOL(tcp_get_cookie_sock);