From b905ef9ab90115d001c1658259af4b1c65088779 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Thu, 19 Apr 2018 12:25:38 -0700 Subject: [PATCH] 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: Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- include/net/llc_conn.h | 1 + net/llc/llc_c_ac.c | 9 +-------- net/llc/llc_conn.c | 22 +++++++++++++++++++++- 3 files changed, 23 insertions(+), 9 deletions(-) diff --git a/include/net/llc_conn.h b/include/net/llc_conn.h index 5c40f118c0fa..df528a623548 100644 --- a/include/net/llc_conn.h +++ b/include/net/llc_conn.h @@ -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); diff --git a/net/llc/llc_c_ac.c b/net/llc/llc_c_ac.c index 163121192aca..4d78375f9872 100644 --- a/net/llc/llc_c_ac.c +++ b/net/llc/llc_c_ac.c @@ -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; } diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c index 110e32bcb399..c0ac522b48a1 100644 --- a/net/llc/llc_conn.c +++ b/net/llc/llc_conn.c @@ -961,6 +961,26 @@ struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct pr 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),