Re: [syzbot] Re: [PATCH v2] Bluetooth: SCO: Use disable_delayed_work_sync

[syzbot <syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com>]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Re: [PATCH v2] Bluetooth: SCO: Use disable_delayed_work_sync
Author: luiz.dentz@gmail.com

#syz test

On Wed, Oct 2, 2024 at 11:40 AM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
>
> This makes use of disable_delayed_work_sync instead
> cancel_delayed_work_sync as it not only cancel the ongoing work but also
> disables new submit which is disarable since the object holding the work
> is about to be freed.
>
> In addition to it remove call to sco_sock_set_timer on __sco_sock_close
> since at that point it is useless to set a timer as the sk will be freed
> there is nothing to be done in sco_sock_timeout.
>
> Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
> Fixes: ba316be1b6a0 ("Bluetooth: schedule SCO timeouts with delayed_work")
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> ---
>  net/bluetooth/sco.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
> index a5ac160c592e..8dfb53dabbd7 100644
> --- a/net/bluetooth/sco.c
> +++ b/net/bluetooth/sco.c
> @@ -208,7 +208,7 @@ static void sco_conn_del(struct hci_conn *hcon, int err)
>         }
>
>         /* Ensure no more work items will run before freeing conn. */
> -       cancel_delayed_work_sync(&conn->timeout_work);
> +       disable_delayed_work_sync(&conn->timeout_work);
>
>         hcon->sco_data = NULL;
>         kfree(conn);
> @@ -444,7 +444,6 @@ static void __sco_sock_close(struct sock *sk)
>         case BT_CONFIG:
>                 if (sco_pi(sk)->conn->hcon) {
>                         sk->sk_state = BT_DISCONN;
> -                       sco_sock_set_timer(sk, SCO_DISCONN_TIMEOUT);
>                         sco_conn_lock(sco_pi(sk)->conn);
>                         hci_conn_drop(sco_pi(sk)->conn->hcon);
>                         sco_pi(sk)->conn->hcon = NULL;
> --
> 2.46.1
>


-- 
Luiz Augusto von Dentz