4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long <lucien.xin@xxxxxxxxx> [ Upstream commit 0c2232b0a71db0ac1d22f751aa1ac0cadb950fd2 ] In dccp_v6_conn_request, after reqsk gets alloced and hashed into ehash table, reqsk's refcnt is set 3. one is for req->rsk_timer, one is for hlist, and the other one is for current using. The problem is when dccp_v6_conn_request returns and finishes using reqsk, it doesn't put reqsk. This will cause reqsk refcnt leaks and reqsk obj never gets freed. Jianlin found this issue when running dccp_memleak.c in a loop, the system memory would run out. dccp_memleak.c: int s1 = socket(PF_INET6, 6, IPPROTO_IP); bind(s1, &sa1, 0x20); listen(s1, 0x9); int s2 = socket(PF_INET6, 6, IPPROTO_IP); connect(s2, &sa1, 0x20); close(s1); close(s2); This patch is to put the reqsk before dccp_v6_conn_request returns, just as what tcp_conn_request does. Reported-by: Jianlin Shi <jishi@xxxxxxxxxx> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/dccp/ipv6.c | 1 + 1 file changed, 1 insertion(+) --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -380,6 +380,7 @@ static int dccp_v6_conn_request(struct s goto drop_and_free; inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); + reqsk_put(req); return 0; drop_and_free: