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
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>

diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
index 0ccf6bf01ed41eb39afcb16af924dca760d360f3..c50b68bbecdc48f46df0641e02898281a23de2d5 100644 (file)
--- 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;

diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
index 32527bdf4b50995445196b8074c96033c9123615..6d41b2023f09d3753921428955c2be9bf37a31c8 100644 (file)
--- 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;

diff --git a/drivers/bluetooth/hci_intel.c b/drivers/bluetooth/hci_intel.c
index aad07e40ea4fda37d39915892f53365702f72ca8..c75311d4dd312ef4b4dec4d25f171690ca0db93f 100644 (file)
--- a/drivers/bluetooth/hci_intel.c
+++ b/drivers/bluetooth/hci_intel.c
@@ -406,6 +406,9 @@ static int intel_open(struct hci_uart *hu)
 
        BT_DBG("hu %p", hu);
 
+       if (!hci_uart_has_flow_control(hu))
+               return -EOPNOTSUPP;
+
        intel = kzalloc(sizeof(*intel), GFP_KERNEL);
        if (!intel)
                return -ENOMEM;

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 3b63a781f10fce4d293422102d5689b348e40389..43221def1d29feafb6a9f77740f9309000b4f5d9 100644 (file)
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -297,6 +297,19 @@ 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)
 {

diff --git a/drivers/bluetooth/hci_mrvl.c b/drivers/bluetooth/hci_mrvl.c
index ffb00669346f0ee70045043e82af0651e80591ba..23791df081bab0935fed1a91ec3e36f67da9f3e7 100644 (file)
--- 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;

diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index 66e8c68e4607d72e462ea0c093dcefd6fb4636d5..e5ec2cf1755ba30b01d7ae074c55c4df27bce963 100644 (file)
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -117,6 +117,7 @@ void hci_uart_unregister_device(struct hci_uart *hu);
 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);