From a14430db686b8e459e1cf070a6ecf391515c9ab9 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Mar 2013 09:21:20 +0100 Subject: [PATCH] USB: mos7840: 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/mos7840.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c index 1b83b01dfb77..b8051fa61911 100644 --- a/drivers/usb/serial/mos7840.c +++ b/drivers/usb/serial/mos7840.c @@ -219,7 +219,6 @@ struct moschip_port { char open; char open_ports; wait_queue_head_t wait_chase; /* for handling sleeping while waiting for chase to finish */ - wait_queue_head_t delta_msr_wait; /* for handling sleeping while waiting for msr change to happen */ int delta_msr_cond; struct async_icount icount; struct usb_serial_port *port; /* loop back to the owner of this object */ @@ -425,7 +424,7 @@ static void mos7840_handle_new_msr(struct moschip_port *port, __u8 new_msr) } mos7840_port->delta_msr_cond = 1; - wake_up_interruptible(&mos7840_port->delta_msr_wait); + wake_up_interruptible(&port->port->delta_msr_wait); } } @@ -1130,7 +1129,6 @@ static int mos7840_open(struct tty_struct *tty, struct usb_serial_port *port) /* initialize our wait queues */ init_waitqueue_head(&mos7840_port->wait_chase); - init_waitqueue_head(&mos7840_port->delta_msr_wait); /* initialize our icount structure */ memset(&(mos7840_port->icount), 0x00, sizeof(mos7840_port->icount)); @@ -2220,13 +2218,18 @@ static int mos7840_ioctl(struct tty_struct *tty, while (1) { /* interruptible_sleep_on(&mos7840_port->delta_msr_wait); */ mos7840_port->delta_msr_cond = 0; - wait_event_interruptible(mos7840_port->delta_msr_wait, - (mos7840_port-> + wait_event_interruptible(port->delta_msr_wait, + (port->serial->disconnected || + mos7840_port-> delta_msr_cond == 1)); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; + + if (port->serial->disconnected) + return -EIO; + cnow = mos7840_port->icount; smp_rmb(); if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && -- GitLab