This is a note to let you know that I've just added the patch titled
USB: mct_u232: fix use-after-free in TIOCMIWAIT
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From cf1d24443677a0758cfa88ca40f24858b89261c0 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@xxxxxxxxx>
Date: Tue, 19 Mar 2013 09:21:18 +0100
Subject: USB: mct_u232: 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@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/mct_u232.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index a64d420..06d5a60 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -114,8 +114,6 @@ struct mct_u232_private {
unsigned char last_msr; /* Modem Status Register */
unsigned int rx_flags; /* Throttling flags */
struct async_icount icount;
- wait_queue_head_t msr_wait; /* for handling sleeping while waiting
- for msr change to happen */
};
#define THROTTLED 0x01
@@ -409,7 +407,6 @@ static int mct_u232_port_probe(struct usb_serial_port *port)
return -ENOMEM;
spin_lock_init(&priv->lock);
- init_waitqueue_head(&priv->msr_wait);
usb_set_serial_port_data(port, priv);
@@ -601,7 +598,7 @@ static void mct_u232_read_int_callback(struct urb *urb)
tty_kref_put(tty);
}
#endif
- wake_up_interruptible(&priv->msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
spin_unlock_irqrestore(&priv->lock, flags);
exit:
retval = usb_submit_urb(urb, GFP_ATOMIC);
@@ -810,13 +807,17 @@ static int mct_u232_ioctl(struct tty_struct *tty,
cprev = mct_u232_port->icount;
spin_unlock_irqrestore(&mct_u232_port->lock, flags);
for ( ; ; ) {
- prepare_to_wait(&mct_u232_port->msr_wait,
+ prepare_to_wait(&port->delta_msr_wait,
&wait, TASK_INTERRUPTIBLE);
schedule();
- finish_wait(&mct_u232_port->msr_wait, &wait);
+ finish_wait(&port->delta_msr_wait, &wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
+
+ if (port->serial->disconnected)
+ return -EIO;
+
spin_lock_irqsave(&mct_u232_port->lock, flags);
cnow = mct_u232_port->icount;
spin_unlock_irqrestore(&mct_u232_port->lock, flags);
--
1.8.0.rc0.18.gf84667d
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html