From fc98ab873aa3dbe783ce56a2ffdbbe7c7609521a Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Mar 2013 09:21:26 +0100 Subject: [PATCH] USB: ti_usb_3410_5052: 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 Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/ti_usb_3410_5052.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c index 39cb9b807c3c..73deb029fc05 100644 --- a/drivers/usb/serial/ti_usb_3410_5052.c +++ b/drivers/usb/serial/ti_usb_3410_5052.c @@ -74,7 +74,6 @@ struct ti_port { int tp_flags; int tp_closing_wait;/* in .01 secs */ struct async_icount tp_icount; - wait_queue_head_t tp_msr_wait; /* wait for msr change */ wait_queue_head_t tp_write_wait; struct ti_device *tp_tdev; struct usb_serial_port *tp_port; @@ -432,7 +431,6 @@ static int ti_port_probe(struct usb_serial_port *port) else tport->tp_uart_base_addr = TI_UART2_BASE_ADDR; tport->tp_closing_wait = closing_wait; - init_waitqueue_head(&tport->tp_msr_wait); init_waitqueue_head(&tport->tp_write_wait); if (kfifo_alloc(&tport->write_fifo, TI_WRITE_BUF_SIZE, GFP_KERNEL)) { kfree(tport); @@ -784,9 +782,13 @@ static int ti_ioctl(struct tty_struct *tty, dev_dbg(&port->dev, "%s - TIOCMIWAIT\n", __func__); cprev = tport->tp_icount; while (1) { - interruptible_sleep_on(&tport->tp_msr_wait); + interruptible_sleep_on(&port->delta_msr_wait); if (signal_pending(current)) return -ERESTARTSYS; + + if (port->serial->disconnected) + return -EIO; + cnow = tport->tp_icount; if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) @@ -1392,7 +1394,7 @@ static void ti_handle_new_msr(struct ti_port *tport, __u8 msr) icount->dcd++; if (msr & TI_MSR_DELTA_RI) icount->rng++; - wake_up_interruptible(&tport->tp_msr_wait); + wake_up_interruptible(&tport->tp_port->delta_msr_wait); spin_unlock_irqrestore(&tport->tp_lock, flags); }