From 43a66b4c417ad15f6d2f632ce67ad195bdf999e8 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Mar 2013 09:21:25 +0100 Subject: [PATCH] USB: ssu100: 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/ssu100.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/ssu100.c b/drivers/usb/serial/ssu100.c index b57cf841c5b6..4b2a19757b4d 100644 --- a/drivers/usb/serial/ssu100.c +++ b/drivers/usb/serial/ssu100.c @@ -61,7 +61,6 @@ struct ssu100_port_private { spinlock_t status_lock; u8 shadowLSR; u8 shadowMSR; - wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */ struct async_icount icount; }; @@ -355,8 +354,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg) spin_unlock_irqrestore(&priv->status_lock, flags); while (1) { - wait_event_interruptible(priv->delta_msr_wait, - ((priv->icount.rng != prev.rng) || + wait_event_interruptible(port->delta_msr_wait, + (port->serial->disconnected || + (priv->icount.rng != prev.rng) || (priv->icount.dsr != prev.dsr) || (priv->icount.dcd != prev.dcd) || (priv->icount.cts != prev.cts))); @@ -364,6 +364,9 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg) if (signal_pending(current)) return -ERESTARTSYS; + if (port->serial->disconnected) + return -EIO; + spin_lock_irqsave(&priv->status_lock, flags); cur = priv->icount; spin_unlock_irqrestore(&priv->status_lock, flags); @@ -445,7 +448,6 @@ static int ssu100_port_probe(struct usb_serial_port *port) return -ENOMEM; spin_lock_init(&priv->status_lock); - init_waitqueue_head(&priv->delta_msr_wait); usb_set_serial_port_data(port, priv); @@ -537,7 +539,7 @@ static void ssu100_update_msr(struct usb_serial_port *port, u8 msr) priv->icount.dcd++; if (msr & UART_MSR_TERI) priv->icount.rng++; - wake_up_interruptible(&priv->delta_msr_wait); + wake_up_interruptible(&port->delta_msr_wait); } }