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| author | Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> | 2021-07-28 10:51:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 12:45:29 +0300 |
| commit | 6f62a0724af684875624191eaedeef390d9c56fe (patch) | |
| tree | f5eeb598bb12035a46b03fbc99e85448f00afc67 /net/bluetooth | |
| parent | c6add598a5dbbc1568b4a6a506d99fe684cb6969 (diff) | |
| download | linux-6f62a0724af684875624191eaedeef390d9c56fe.tar.xz | |
Bluetooth: skip invalid hci_sync_conn_complete_evt
[ Upstream commit 92fe24a7db751b80925214ede43f8d2be792ea7b ]
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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/hci_event.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index b3253f2e11af..5186f199d892 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -3761,6 +3761,21 @@ static void hci_sync_conn_complete_evt(struct hci_dev *hdev, switch (ev->status) { case 0x00: + /* The synchronous connection complete event should only be + * sent once per new connection. Receiving a successful + * complete event when the connection status is already + * BT_CONNECTED means that the device is misbehaving and sent + * multiple complete event packets for the same new connection. + * + * Registering the device more than once can corrupt kernel + * memory, hence upon detecting this invalid event, we report + * an error and ignore the packet. + */ + if (conn->state == BT_CONNECTED) { + bt_dev_err(hdev, "Ignoring connect complete event for existing connection"); + goto unlock; + } + conn->handle = __le16_to_cpu(ev->handle); conn->state = BT_CONNECTED; conn->type = ev->link_type; |