llc: delete timers synchronously in llc_sk_free()

The connection timers of an llc sock could be still flying
after we delete them in llc_sk_free(), and even possibly
after we free the sock. We could just wait synchronously
here in case of troubles.

Note, I leave other call paths as they are, since they may
not have to wait, at least we can change them to synchronously
when needed.

Also, move the code to net/llc/llc_conn.c, which is apparently
a better place.

Reported-by: <syzbot+f922284c18ea23a8e457@syzkaller.appspotmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2018-04-19 12:25:38 -07:00 committed by David S. Miller
parent 5411b6187a
commit b905ef9ab9
3 changed files with 23 additions and 9 deletions

View File

@ -97,6 +97,7 @@ static __inline__ char llc_backlog_type(struct sk_buff *skb)
struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority,
struct proto *prot, int kern);
void llc_sk_stop_all_timers(struct sock *sk, bool sync);
void llc_sk_free(struct sock *sk);
void llc_sk_reset(struct sock *sk);

View File

@ -1099,14 +1099,7 @@ int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
del_timer(&llc->pf_cycle_timer.timer);
del_timer(&llc->ack_timer.timer);
del_timer(&llc->rej_sent_timer.timer);
del_timer(&llc->busy_state_timer.timer);
llc->ack_must_be_send = 0;
llc->ack_pf = 0;
llc_sk_stop_all_timers(sk, false);
return 0;
}

View File

@ -961,6 +961,26 @@ out:
return sk;
}
void llc_sk_stop_all_timers(struct sock *sk, bool sync)
{
struct llc_sock *llc = llc_sk(sk);
if (sync) {
del_timer_sync(&llc->pf_cycle_timer.timer);
del_timer_sync(&llc->ack_timer.timer);
del_timer_sync(&llc->rej_sent_timer.timer);
del_timer_sync(&llc->busy_state_timer.timer);
} else {
del_timer(&llc->pf_cycle_timer.timer);
del_timer(&llc->ack_timer.timer);
del_timer(&llc->rej_sent_timer.timer);
del_timer(&llc->busy_state_timer.timer);
}
llc->ack_must_be_send = 0;
llc->ack_pf = 0;
}
/**
* llc_sk_free - Frees a LLC socket
* @sk - socket to free
@ -973,7 +993,7 @@ void llc_sk_free(struct sock *sk)
llc->state = LLC_CONN_OUT_OF_SVC;
/* Stop all (possibly) running timers */
llc_conn_ac_stop_all_timers(sk, NULL);
llc_sk_stop_all_timers(sk, true);
#ifdef DEBUG_LLC_CONN_ALLOC
printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __func__,
skb_queue_len(&llc->pdu_unack_q),