When processing options from tcp reset path its possible that
tcp_done(ssk) drops the last reference on the mptcp socket which
results in use-after-free.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
struct sock *sk = subflow->conn;
+ /* must hold: tcp_done() could drop last reference on parent */
+ sock_hold(sk);
+
tcp_set_state(ssk, TCP_CLOSE);
tcp_send_active_reset(ssk, GFP_ATOMIC);
tcp_done(ssk);
if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) &&
schedule_work(&mptcp_sk(sk)->work))
- sock_hold(sk);
+ return; /* worker will put sk for us */
+
+ sock_put(sk);
}
static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)