From: Vladis Dronov vdronov@redhat.com
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=1b42faa2848963564a5b1b7f8c837ea7b55ffa5... 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 vdronov@redhat.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Reviewed-by: Yu-Chen, Cho acho@suse.com Tested-by: Yu-Chen, Cho acho@suse.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/bluetooth/hci_ath.c | 3 +++ drivers/bluetooth/hci_bcm.c | 3 +++ drivers/bluetooth/hci_intel.c | 3 +++ drivers/bluetooth/hci_ldisc.c | 13 +++++++++++++ drivers/bluetooth/hci_mrvl.c | 3 +++ drivers/bluetooth/hci_uart.h | 1 + 6 files changed, 26 insertions(+)
--- a/drivers/bluetooth/hci_ath.c +++ b/drivers/bluetooth/hci_ath.c @@ -101,6 +101,9 @@ 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; --- a/drivers/bluetooth/hci_bcm.c +++ b/drivers/bluetooth/hci_bcm.c @@ -305,6 +305,9 @@ static int bcm_open(struct hci_uart *hu)
bt_dev_dbg(hu->hdev, "hu %p", hu);
+ if (!hci_uart_has_flow_control(hu)) + return -EOPNOTSUPP; + bcm = kzalloc(sizeof(*bcm), GFP_KERNEL); if (!bcm) return -ENOMEM; --- a/drivers/bluetooth/hci_intel.c +++ b/drivers/bluetooth/hci_intel.c @@ -406,6 +406,9 @@ static int intel_open(struct hci_uart *h
BT_DBG("hu %p", hu);
+ if (!hci_uart_has_flow_control(hu)) + return -EOPNOTSUPP; + intel = kzalloc(sizeof(*intel), GFP_KERNEL); if (!intel) return -ENOMEM; --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -297,6 +297,19 @@ static int hci_uart_send_frame(struct hc 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) { --- a/drivers/bluetooth/hci_mrvl.c +++ b/drivers/bluetooth/hci_mrvl.c @@ -66,6 +66,9 @@ static int mrvl_open(struct hci_uart *hu
BT_DBG("hu %p", hu);
+ if (!hci_uart_has_flow_control(hu)) + return -EOPNOTSUPP; + mrvl = kzalloc(sizeof(*mrvl), GFP_KERNEL); if (!mrvl) return -ENOMEM; --- a/drivers/bluetooth/hci_uart.h +++ b/drivers/bluetooth/hci_uart.h @@ -117,6 +117,7 @@ void hci_uart_unregister_device(struct h int hci_uart_tx_wakeup(struct hci_uart *hu); int hci_uart_init_ready(struct hci_uart *hu); void hci_uart_set_baudrate(struct hci_uart *hu, unsigned int speed); +bool hci_uart_has_flow_control(struct hci_uart *hu); void hci_uart_set_flow_control(struct hci_uart *hu, bool enable); void hci_uart_set_speeds(struct hci_uart *hu, unsigned int init_speed, unsigned int oper_speed);