From b36a1552d7319bbfd5cf7f08726c23c5c66d4f73 Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Tue, 30 Jul 2019 11:33:45 +0200 Subject: Bluetooth: hci_uart: check for missing tty operations Certain ttys operations (pty_unix98_ops) lack tiocmget() and tiocmset() functions which are called by the certain HCI UART protocols (hci_ath, hci_bcm, hci_intel, hci_mrvl, hci_qca) via hci_uart_set_flow_control() or directly. This leads to an execution at NULL and can be triggered by an unprivileged user. Fix this by adding a helper function and a check for the missing tty operations in the protocols code. This fixes CVE-2019-10207. The Fixes: lines list commits where calls to tiocm[gs]et() or hci_uart_set_flow_control() were added to the HCI UART protocols. Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50 Reported-by: syzbot+79337b501d6aa974d0f6@syzkaller.appspotmail.com Cc: stable@vger.kernel.org # v2.6.36+ Fixes: b3190df62861 ("Bluetooth: Support for Atheros AR300x serial chip") Fixes: 118612fb9165 ("Bluetooth: hci_bcm: Add suspend/resume PM functions") Fixes: ff2895592f0f ("Bluetooth: hci_intel: Add Intel baudrate configuration support") Fixes: 162f812f23ba ("Bluetooth: hci_uart: Add Marvell support") Fixes: fa9ad876b8e0 ("Bluetooth: hci_qca: Add support for Qualcomm Bluetooth chip wcn3990") Signed-off-by: Vladis Dronov Signed-off-by: Marcel Holtmann Reviewed-by: Yu-Chen, Cho Tested-by: Yu-Chen, Cho Signed-off-by: Linus Torvalds --- drivers/bluetooth/hci_ldisc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'drivers/bluetooth/hci_ldisc.c') diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 8950e07889fe..85a30fb9177b 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -292,6 +292,19 @@ static int hci_uart_send_frame(struct hci_dev *hdev, struct sk_buff *skb) return 0; } +/* Check the underlying device or tty has flow control support */ +bool hci_uart_has_flow_control(struct hci_uart *hu) +{ + /* serdev nodes check if the needed operations are present */ + if (hu->serdev) + return true; + + if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset) + return true; + + return false; +} + /* Flow control or un-flow control the device */ void hci_uart_set_flow_control(struct hci_uart *hu, bool enable) { -- cgit v1.2.3