From: Vladis Dronov Date: Tue, 30 Jul 2019 09:33:45 +0000 (+0200) Subject: Bluetooth: hci_uart: check for missing tty operations X-Git-Tag: v3.16.72~23 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebb8302ce770e8c455d9209cb598f4cd03021e42;p=thirdparty%2Fkernel%2Fstable.git Bluetooth: hci_uart: check for missing tty operations commit b36a1552d7319bbfd5cf7f08726c23c5c66d4f73 upstream. 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 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 [bwh: Backported to 3.16: - Only hci_ath is affected - There is no serdev support] Signed-off-by: Ben Hutchings --- diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c index 0bc8a6a6a1485..353ed68db711e 100644 --- a/drivers/bluetooth/hci_ath.c +++ b/drivers/bluetooth/hci_ath.c @@ -112,6 +112,9 @@ static int ath_open(struct hci_uart *hu) BT_DBG("hu %p", hu); + if (!hci_uart_has_flow_control(hu)) + return -EOPNOTSUPP; + ath = kzalloc(sizeof(*ath), GFP_KERNEL); if (!ath) return -ENOMEM; diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index e00f8f5b5c8e1..9ad437053e222 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -261,6 +261,15 @@ 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) +{ + if (hu->tty->driver->ops->tiocmget && hu->tty->driver->ops->tiocmset) + return true; + + return false; +} + /* ------ LDISC part ------ */ /* hci_uart_tty_open * diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h index 12df101ca942d..58e0bb8c041b2 100644 --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -90,6 +90,7 @@ int hci_uart_register_proto(struct hci_uart_proto *p); int hci_uart_unregister_proto(struct hci_uart_proto *p); int hci_uart_tx_wakeup(struct hci_uart *hu); int hci_uart_init_ready(struct hci_uart *hu); +bool hci_uart_has_flow_control(struct hci_uart *hu); #ifdef CONFIG_BT_HCIUART_H4 int h4_init(void);