Re: [PATCH v3] Bluetooth: SCO: Use disable_delayed_work_sync

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

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#syz test

On Wed, Oct 2, 2024 at 3:46 PM Luiz Augusto von Dentz
<luiz.dentz@gmail.com> wrote:
>
> #syz test
>
> On Wed, Oct 2, 2024 at 3:19 PM Luiz Augusto von Dentz
> <luiz.dentz@gmail.com> wrote:
> >
> > #syz test
> >
> > On Wed, Oct 2, 2024 at 3:04 PM 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 | 13 +------------
> > >  1 file changed, 1 insertion(+), 12 deletions(-)
> > >
> > > diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
> > > index a5ac160c592e..2b1e66976068 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);
> > > @@ -442,17 +442,6 @@ static void __sco_sock_close(struct sock *sk)
> > >
> > >         case BT_CONNECTED:
> > >         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;
> > > -                       sco_conn_unlock(sco_pi(sk)->conn);
> > > -               } else
> > > -                       sco_chan_del(sk, ECONNRESET);
> > > -               break;
> > > -
> > >         case BT_CONNECT2:
> > >         case BT_CONNECT:
> > >         case BT_DISCONN:
> > > --
> > > 2.46.1
> > >
> >
> >
> > --
> > Luiz Augusto von Dentz
>
>
>
> --
> Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz

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From 85b438673dd4f1bb68676294d5674d20a0d47c09 Mon Sep 17 00:00:00 2001
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date: Tue, 1 Oct 2024 15:46:10 -0400
Subject: [PATCH v4] Bluetooth: SCO: Use disable_delayed_work_sync

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 | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index a5ac160c592e..cee87c6c9194 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -169,10 +169,11 @@ static void sco_chan_del(struct sock *sk, int err)
 		sco_conn_lock(conn);
 		conn->sk = NULL;
 		sco_pi(sk)->conn = NULL;
-		sco_conn_unlock(conn);
-
-		if (conn->hcon)
+		if (conn->hcon) {
 			hci_conn_drop(conn->hcon);
+			conn->hcon = NULL;
+		}
+		sco_conn_unlock(conn);
 	}
 
 	sk->sk_state = BT_CLOSED;
@@ -208,7 +209,7 @@ 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);
@@ -442,17 +443,6 @@ static void __sco_sock_close(struct sock *sk)
 
 	case BT_CONNECTED:
 	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;
-			sco_conn_unlock(sco_pi(sk)->conn);
-		} else
-			sco_chan_del(sk, ECONNRESET);
-		break;
-
 	case BT_CONNECT2:
 	case BT_CONNECT:
 	case BT_DISCONN:
-- 
2.46.1