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![Nguyen Dinh Phi](/assets/img/avatar_default.png)
Commit63346650c1
("netrom: switch to sock timer API") switched to use sock timer API. It replaces mod_timer() by sk_reset_timer(), and del_timer() by sk_stop_timer(). Function sk_reset_timer() will increase the refcount of sock if it is called on an inactive timer, hence, in case the timer expires, we need to decrease the refcount ourselves in the handler, otherwise, the sock refcount will be unbalanced and the sock will never be freed. Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com> Reported-by: syzbot+10f1194569953b72f1ae@syzkaller.appspotmail.com Fixes:63346650c1
("netrom: switch to sock timer API") Signed-off-by: David S. Miller <davem@davemloft.net>
247 lines
5.2 KiB
C
247 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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*
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* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
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* Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/jiffies.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <net/ax25.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <net/tcp_states.h>
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#include <linux/uaccess.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <net/netrom.h>
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static void nr_heartbeat_expiry(struct timer_list *);
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static void nr_t1timer_expiry(struct timer_list *);
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static void nr_t2timer_expiry(struct timer_list *);
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static void nr_t4timer_expiry(struct timer_list *);
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static void nr_idletimer_expiry(struct timer_list *);
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void nr_init_timers(struct sock *sk)
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{
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struct nr_sock *nr = nr_sk(sk);
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timer_setup(&nr->t1timer, nr_t1timer_expiry, 0);
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timer_setup(&nr->t2timer, nr_t2timer_expiry, 0);
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timer_setup(&nr->t4timer, nr_t4timer_expiry, 0);
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timer_setup(&nr->idletimer, nr_idletimer_expiry, 0);
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/* initialized by sock_init_data */
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sk->sk_timer.function = nr_heartbeat_expiry;
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}
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void nr_start_t1timer(struct sock *sk)
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{
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struct nr_sock *nr = nr_sk(sk);
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sk_reset_timer(sk, &nr->t1timer, jiffies + nr->t1);
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}
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void nr_start_t2timer(struct sock *sk)
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{
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struct nr_sock *nr = nr_sk(sk);
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sk_reset_timer(sk, &nr->t2timer, jiffies + nr->t2);
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}
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void nr_start_t4timer(struct sock *sk)
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{
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struct nr_sock *nr = nr_sk(sk);
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sk_reset_timer(sk, &nr->t4timer, jiffies + nr->t4);
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}
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void nr_start_idletimer(struct sock *sk)
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{
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struct nr_sock *nr = nr_sk(sk);
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if (nr->idle > 0)
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sk_reset_timer(sk, &nr->idletimer, jiffies + nr->idle);
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}
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void nr_start_heartbeat(struct sock *sk)
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{
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sk_reset_timer(sk, &sk->sk_timer, jiffies + 5 * HZ);
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}
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void nr_stop_t1timer(struct sock *sk)
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{
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sk_stop_timer(sk, &nr_sk(sk)->t1timer);
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}
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void nr_stop_t2timer(struct sock *sk)
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{
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sk_stop_timer(sk, &nr_sk(sk)->t2timer);
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}
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void nr_stop_t4timer(struct sock *sk)
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{
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sk_stop_timer(sk, &nr_sk(sk)->t4timer);
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}
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void nr_stop_idletimer(struct sock *sk)
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{
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sk_stop_timer(sk, &nr_sk(sk)->idletimer);
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}
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void nr_stop_heartbeat(struct sock *sk)
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{
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sk_stop_timer(sk, &sk->sk_timer);
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}
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int nr_t1timer_running(struct sock *sk)
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{
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return timer_pending(&nr_sk(sk)->t1timer);
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}
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static void nr_heartbeat_expiry(struct timer_list *t)
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{
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struct sock *sk = from_timer(sk, t, sk_timer);
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struct nr_sock *nr = nr_sk(sk);
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bh_lock_sock(sk);
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switch (nr->state) {
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case NR_STATE_0:
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/* Magic here: If we listen() and a new link dies before it
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is accepted() it isn't 'dead' so doesn't get removed. */
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if (sock_flag(sk, SOCK_DESTROY) ||
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(sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
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bh_unlock_sock(sk);
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nr_destroy_socket(sk);
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goto out;
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}
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break;
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case NR_STATE_3:
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/*
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* Check for the state of the receive buffer.
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*/
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if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
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(nr->condition & NR_COND_OWN_RX_BUSY)) {
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nr->condition &= ~NR_COND_OWN_RX_BUSY;
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nr->condition &= ~NR_COND_ACK_PENDING;
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nr->vl = nr->vr;
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nr_write_internal(sk, NR_INFOACK);
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break;
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}
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break;
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}
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nr_start_heartbeat(sk);
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bh_unlock_sock(sk);
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out:
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sock_put(sk);
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}
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static void nr_t2timer_expiry(struct timer_list *t)
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{
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struct nr_sock *nr = from_timer(nr, t, t2timer);
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struct sock *sk = &nr->sock;
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bh_lock_sock(sk);
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if (nr->condition & NR_COND_ACK_PENDING) {
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nr->condition &= ~NR_COND_ACK_PENDING;
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nr_enquiry_response(sk);
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}
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bh_unlock_sock(sk);
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sock_put(sk);
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}
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static void nr_t4timer_expiry(struct timer_list *t)
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{
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struct nr_sock *nr = from_timer(nr, t, t4timer);
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struct sock *sk = &nr->sock;
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bh_lock_sock(sk);
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nr_sk(sk)->condition &= ~NR_COND_PEER_RX_BUSY;
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bh_unlock_sock(sk);
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sock_put(sk);
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}
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static void nr_idletimer_expiry(struct timer_list *t)
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{
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struct nr_sock *nr = from_timer(nr, t, idletimer);
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struct sock *sk = &nr->sock;
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bh_lock_sock(sk);
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nr_clear_queues(sk);
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nr->n2count = 0;
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nr_write_internal(sk, NR_DISCREQ);
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nr->state = NR_STATE_2;
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nr_start_t1timer(sk);
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nr_stop_t2timer(sk);
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nr_stop_t4timer(sk);
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sk->sk_state = TCP_CLOSE;
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sk->sk_err = 0;
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sk->sk_shutdown |= SEND_SHUTDOWN;
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if (!sock_flag(sk, SOCK_DEAD)) {
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sk->sk_state_change(sk);
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sock_set_flag(sk, SOCK_DEAD);
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}
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bh_unlock_sock(sk);
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sock_put(sk);
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}
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static void nr_t1timer_expiry(struct timer_list *t)
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{
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struct nr_sock *nr = from_timer(nr, t, t1timer);
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struct sock *sk = &nr->sock;
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bh_lock_sock(sk);
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switch (nr->state) {
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case NR_STATE_1:
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if (nr->n2count == nr->n2) {
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nr_disconnect(sk, ETIMEDOUT);
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goto out;
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} else {
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nr->n2count++;
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nr_write_internal(sk, NR_CONNREQ);
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}
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break;
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case NR_STATE_2:
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if (nr->n2count == nr->n2) {
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nr_disconnect(sk, ETIMEDOUT);
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goto out;
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} else {
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nr->n2count++;
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nr_write_internal(sk, NR_DISCREQ);
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}
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break;
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case NR_STATE_3:
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if (nr->n2count == nr->n2) {
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nr_disconnect(sk, ETIMEDOUT);
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goto out;
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} else {
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nr->n2count++;
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nr_requeue_frames(sk);
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}
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break;
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}
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nr_start_t1timer(sk);
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out:
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bh_unlock_sock(sk);
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sock_put(sk);
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}
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