[PATCH 4.4 37/65] netrom: switch to sock timer API

Greg Kroah-Hartman
2019-02-04T10:40:59Z

From: Cong Wang <xiyou.wangcong@gmail.com>

[ Upstream commit 63346650c1a94a92be61a57416ac88c0a47c4327 ]

sk_reset_timer() and sk_stop_timer() properly handle
sock refcnt for timer function. Switching to them
could fix a refcounting bug reported by syzbot.

Reported-and-tested-by: syzbot+defa700d16f1bd1b9a05@syzkaller.appspotmail.com
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netrom/nr_timer.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

--- a/net/netrom/nr_timer.c
+++ b/net/netrom/nr_timer.c
@@ -53,21 +53,21 @@ void nr_start_t1timer(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);

- mod_timer(&nr->t1timer, jiffies + nr->t1);
+ sk_reset_timer(sk, &nr->t1timer, jiffies + nr->t1);
}

void nr_start_t2timer(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);

- mod_timer(&nr->t2timer, jiffies + nr->t2);
+ sk_reset_timer(sk, &nr->t2timer, jiffies + nr->t2);
}

void nr_start_t4timer(struct sock *sk)
{
struct nr_sock *nr = nr_sk(sk);

- mod_timer(&nr->t4timer, jiffies + nr->t4);
+ sk_reset_timer(sk, &nr->t4timer, jiffies + nr->t4);
}

void nr_start_idletimer(struct sock *sk)
@@ -75,37 +75,37 @@ void nr_start_idletimer(struct sock *sk)
struct nr_sock *nr = nr_sk(sk);

if (nr->idle > 0)
- mod_timer(&nr->idletimer, jiffies + nr->idle);
+ sk_reset_timer(sk, &nr->idletimer, jiffies + nr->idle);
}

void nr_start_heartbeat(struct sock *sk)
{
- mod_timer(&sk->sk_timer, jiffies + 5 * HZ);
+ sk_reset_timer(sk, &sk->sk_timer, jiffies + 5 * HZ);
}

void nr_stop_t1timer(struct sock *sk)
{
- del_timer(&nr_sk(sk)->t1timer);
+ sk_stop_timer(sk, &nr_sk(sk)->t1timer);
}

void nr_stop_t2timer(struct sock *sk)
{
- del_timer(&nr_sk(sk)->t2timer);
+ sk_stop_timer(sk, &nr_sk(sk)->t2timer);
}

void nr_stop_t4timer(struct sock *sk)
{
- del_timer(&nr_sk(sk)->t4timer);
+ sk_stop_timer(sk, &nr_sk(sk)->t4timer);
}

void nr_stop_idletimer(struct sock *sk)
{
- del_timer(&nr_sk(sk)->idletimer);
+ sk_stop_timer(sk, &nr_sk(sk)->idletimer);
}

void nr_stop_heartbeat(struct sock *sk)
{
- del_timer(&sk->sk_timer);
+ sk_stop_timer(sk, &sk->sk_timer);
}

int nr_t1timer_running(struct sock *sk)