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From: Marcel Holtmann <marcel@holtmann.org>
To: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-bluetooth <linux-bluetooth@vger.kernel.org>,
	"open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	skhan@linuxfoundation.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Subject: Re: [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt
Date: Thu, 29 Jul 2021 13:38:50 +0200	[thread overview]
Message-ID: <72819085-5564-4386-AD94-2901083CDE65@holtmann.org> (raw)
In-Reply-To: <20210728075105.415214-1-desmondcheongzx@gmail.com>

Hi Desmond,

> Syzbot reported a corrupted list in kobject_add_internal [1]. This
> happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
> status 0 are sent for the same HCI connection. This causes us to
> register the device more than once which corrupts the kset list.
> 
> As this is forbidden behavior, we add a check for whether we're
> trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
> times for one connection. If that's the case, the event is invalid, so
> we report an error that the device is misbehaving, and ignore the
> packet.
> 
> Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
> Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
> ---
> 
> v1 -> v2:
> - Added more comments to explain the reasoning behind the new check, and
> a bt_dev_err message upon detecting the invalid event. As suggested by
> Marcel Holtmann.
> 
> net/bluetooth/hci_event.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)

I shortened the error message and then applied your patch to bluetooth-next tree.

Regards

Marcel


WARNING: multiple messages have this Message-ID
From: Marcel Holtmann <marcel@holtmann.org>
To: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Cc: Johan Hedberg <johan.hedberg@gmail.com>,
	"open list:NETWORKING \[GENERAL\]" <netdev@vger.kernel.org>,
	syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com,
	open list <linux-kernel@vger.kernel.org>,
	linux-bluetooth <linux-bluetooth@vger.kernel.org>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt
Date: Thu, 29 Jul 2021 13:38:50 +0200	[thread overview]
Message-ID: <72819085-5564-4386-AD94-2901083CDE65@holtmann.org> (raw)
In-Reply-To: <20210728075105.415214-1-desmondcheongzx@gmail.com>

Hi Desmond,

> Syzbot reported a corrupted list in kobject_add_internal [1]. This
> happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
> status 0 are sent for the same HCI connection. This causes us to
> register the device more than once which corrupts the kset list.
> 
> As this is forbidden behavior, we add a check for whether we're
> trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
> times for one connection. If that's the case, the event is invalid, so
> we report an error that the device is misbehaving, and ignore the
> packet.
> 
> Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
> Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
> Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
> ---
> 
> v1 -> v2:
> - Added more comments to explain the reasoning behind the new check, and
> a bt_dev_err message upon detecting the invalid event. As suggested by
> Marcel Holtmann.
> 
> net/bluetooth/hci_event.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)

I shortened the error message and then applied your patch to bluetooth-next tree.

Regards

Marcel

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https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

  parent reply	other threads:[~2021-07-29 11:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-28  7:51 [PATCH v2] Bluetooth: skip invalid hci_sync_conn_complete_evt Desmond Cheong Zhi Xi
2021-07-28  7:51 ` Desmond Cheong Zhi Xi
2021-07-28  9:07 ` [v2] " bluez.test.bot
2021-07-29 11:38 ` Marcel Holtmann [this message]
2021-07-29 11:38   ` [PATCH v2] " Marcel Holtmann

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