From: Vladis Dronov <vdronov@redhat.com>
To: Marcel Holtmann <marcel@holtmann.org>,
Johan Hedberg <johan.hedberg@gmail.com>,
linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+79337b501d6aa974d0f6@syzkaller.appspotmail.com,
stable@vger.kernel.org, Loic Poulain <loic.poulain@intel.com>,
Ilya Faenson <ifaenson@broadcom.com>
Subject: [PATCH] Bluetooth: hci_ldisc: check for missing tty operations
Date: Tue, 25 Jun 2019 19:32:15 +0200 [thread overview]
Message-ID: <20190625173215.25999-1-vdronov@redhat.com> (raw)
Certain ttys lack operations (eg: pty_unix98_ops) which still can be
called by certain hci uart proto (eg: mrvl, ath). Currently this leads
to execution at address 0x0. Fix this by adding checks for missing tty
operations.
Link: https://syzkaller.appspot.com/bug?id=1b42faa2848963564a5b1b7f8c837ea7b55ffa50
Reported-by: syzbot+79337b501d6aa974d0f6@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # v2.6.39+
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
---
drivers/bluetooth/hci_ath.c | 7 ++++-
drivers/bluetooth/hci_ldisc.c | 58 ++++++++++++++++++++---------------
2 files changed, 39 insertions(+), 26 deletions(-)
diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
index a55be205b91a..92d9bded5880 100644
--- a/drivers/bluetooth/hci_ath.c
+++ b/drivers/bluetooth/hci_ath.c
@@ -49,7 +49,12 @@ struct ath_vendor_cmd {
static int ath_wakeup_ar3k(struct tty_struct *tty)
{
- int status = tty->driver->ops->tiocmget(tty);
+ int status;
+
+ if (!(tty->driver->ops->tiocmget && tty->driver->ops->tiocmset))
+ return TIOCM_CTS;
+
+ status = tty->driver->ops->tiocmget(tty);
if (status & TIOCM_CTS)
return status;
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index c84f985f348d..29b4970f9bca 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -307,32 +307,40 @@ void hci_uart_set_flow_control(struct hci_uart *hu, bool enable)
BT_DBG("Disabling hardware flow control: %s",
status ? "failed" : "success");
- /* Clear RTS to prevent the device from sending */
- /* Most UARTs need OUT2 to enable interrupts */
- status = tty->driver->ops->tiocmget(tty);
- BT_DBG("Current tiocm 0x%x", status);
-
- set &= ~(TIOCM_OUT2 | TIOCM_RTS);
- clear = ~set;
- set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
- TIOCM_OUT2 | TIOCM_LOOP;
- clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
- TIOCM_OUT2 | TIOCM_LOOP;
- status = tty->driver->ops->tiocmset(tty, set, clear);
- BT_DBG("Clearing RTS: %s", status ? "failed" : "success");
+ if (tty->driver->ops->tiocmget && tty->driver->ops->tiocmset) {
+ /* Clear RTS to prevent the device from sending */
+ /* Most UARTs need OUT2 to enable interrupts */
+ status = tty->driver->ops->tiocmget(tty);
+ BT_DBG("Current tiocm 0x%x", status);
+
+ set &= ~(TIOCM_OUT2 | TIOCM_RTS);
+ clear = ~set;
+ set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
+ TIOCM_OUT2 | TIOCM_LOOP;
+ clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
+ TIOCM_OUT2 | TIOCM_LOOP;
+ status = tty->driver->ops->tiocmset(tty, set, clear);
+ BT_DBG("Clearing RTS: %s",
+ status ? "failed" : "success");
+ } else
+ BT_DBG("Terminal RTS control is not present");
} else {
- /* Set RTS to allow the device to send again */
- status = tty->driver->ops->tiocmget(tty);
- BT_DBG("Current tiocm 0x%x", status);
-
- set |= (TIOCM_OUT2 | TIOCM_RTS);
- clear = ~set;
- set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
- TIOCM_OUT2 | TIOCM_LOOP;
- clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
- TIOCM_OUT2 | TIOCM_LOOP;
- status = tty->driver->ops->tiocmset(tty, set, clear);
- BT_DBG("Setting RTS: %s", status ? "failed" : "success");
+ if (tty->driver->ops->tiocmget && tty->driver->ops->tiocmset) {
+ /* Set RTS to allow the device to send again */
+ status = tty->driver->ops->tiocmget(tty);
+ BT_DBG("Current tiocm 0x%x", status);
+
+ set |= (TIOCM_OUT2 | TIOCM_RTS);
+ clear = ~set;
+ set &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
+ TIOCM_OUT2 | TIOCM_LOOP;
+ clear &= TIOCM_DTR | TIOCM_RTS | TIOCM_OUT1 |
+ TIOCM_OUT2 | TIOCM_LOOP;
+ status = tty->driver->ops->tiocmset(tty, set, clear);
+ BT_DBG("Setting RTS: %s",
+ status ? "failed" : "success");
+ } else
+ BT_DBG("Terminal RTS control is not present");
/* Re-enable hardware flow control */
ktermios = tty->termios;
--
2.20.1
next reply other threads:[~2019-06-25 17:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 17:32 Vladis Dronov [this message]
2019-07-06 10:35 ` Marcel Holtmann
2019-07-06 15:19 ` Vladis Dronov
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