Hi Vladis, > 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 check for the missing tty > operations to the protocols which use them. > > This fixes CVE-2019-10207. > > Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50 > Reported-by: syzbot+79337b501d6aa974d0f6@xxxxxxxxxxxxxxxxxxxxxxxxx > Cc: stable@xxxxxxxxxxxxxxx # 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@xxxxxxxxxx> > --- > drivers/bluetooth/hci_ath.c | 3 +++ > drivers/bluetooth/hci_bcm.c | 5 +++++ > drivers/bluetooth/hci_intel.c | 3 +++ > drivers/bluetooth/hci_mrvl.c | 3 +++ > drivers/bluetooth/hci_qca.c | 4 ++++ > 5 files changed, 18 insertions(+) > > diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c > index a55be205b91a..99df8a13e47e 100644 > --- a/drivers/bluetooth/hci_ath.c > +++ b/drivers/bluetooth/hci_ath.c > @@ -98,6 +98,9 @@ static int ath_open(struct hci_uart *hu) > > BT_DBG("hu %p", hu); > > + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset) > + return -ENOTSUPP; > + > 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 8905ad2edde7..8c3e09cc341c 100644 > --- a/drivers/bluetooth/hci_bcm.c > +++ b/drivers/bluetooth/hci_bcm.c > @@ -406,6 +406,11 @@ static int bcm_open(struct hci_uart *hu) > > bt_dev_dbg(hu->hdev, "hu %p", hu); > > +#ifdef CONFIG_PM > + if (!hu->tty->driver->ops->tiocmget || !hu->tty->driver->ops->tiocmset) > + return -ENOTSUPP; > +#endif > + why is this one hidden behind CONFIG_PM? The general baud rate changes are independent of runtime power management support. And I would introduce a bool hci_uart_has_tiocm_support(struct hci_uart *) helper. Regards Marcel
