USB: io_ti: fix use-after-free in TIOCMIWAIT
Use the port wait queue and make sure to check the serial disconnected
flag before accessing private port data after waking up.
This is is needed as the private port data (including the wait queue
itself) can be gone when waking up after a disconnect.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index d7d3c0e..7777172 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -87,9 +87,6 @@
int close_pending;
int lsr_event;
struct async_icount icount;
- wait_queue_head_t delta_msr_wait; /* for handling sleeping while
- waiting for msr change to
- happen */
struct edgeport_serial *edge_serial;
struct usb_serial_port *port;
__u8 bUartMode; /* Port type, 0: RS232, etc. */
@@ -1459,7 +1456,7 @@
icount->dcd++;
if (msr & EDGEPORT_MSR_DELTA_RI)
icount->rng++;
- wake_up_interruptible(&edge_port->delta_msr_wait);
+ wake_up_interruptible(&edge_port->port->delta_msr_wait);
}
/* Save the new modem status */
@@ -1754,7 +1751,6 @@
dev = port->serial->dev;
memset(&(edge_port->icount), 0x00, sizeof(edge_port->icount));
- init_waitqueue_head(&edge_port->delta_msr_wait);
/* turn off loopback */
status = ti_do_config(edge_port, UMPC_SET_CLR_LOOPBACK, 0);
@@ -2434,10 +2430,14 @@
dev_dbg(&port->dev, "%s - TIOCMIWAIT\n", __func__);
cprev = edge_port->icount;
while (1) {
- interruptible_sleep_on(&edge_port->delta_msr_wait);
+ interruptible_sleep_on(&port->delta_msr_wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
+
+ if (port->serial->disconnected)
+ return -EIO;
+
cnow = edge_port->icount;
if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)