This is a note to let you know that I've just added the patch titled
USB: ftdi_sio: fix use-after-free in TIOCMIWAIT
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-ftdi_sio-fix-use-after-free-in-tiocmiwait.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 31b9905f62ed5c361a37bb6f59cbf414873da65b Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@xxxxxxxxx>
Date: Tue, 19 Mar 2013 09:21:15 +0100
Subject: USB: ftdi_sio: fix use-after-free in TIOCMIWAIT
From: Johan Hovold <jhovold@xxxxxxxxx>
commit 71ccb9b01981fabae27d3c98260ea4613207618e upstream.
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.
When switching to tty ports, some lifetime assumptions were changed.
Specifically, close can now be called before the final tty reference is
dropped as part of hangup at device disconnect. Even with the ftdi
private-data refcounting this means that the port private data can be
freed while a process is sleeping on modem-status changes and thus
cannot be relied on to detect disconnects when woken up.
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/ftdi_sio.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -74,9 +74,7 @@ struct ftdi_private {
int flags; /* some ASYNC_xxxx flags are supported */
unsigned long last_dtr_rts; /* saved modem control outputs */
struct async_icount icount;
- wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
char prev_status; /* Used for TIOCMIWAIT */
- bool dev_gone; /* Used to abort TIOCMIWAIT */
char transmit_empty; /* If transmitter is empty or not */
struct usb_serial_port *port;
__u16 interface; /* FT2232C, FT2232H or FT4232H port interface
@@ -1746,10 +1744,8 @@ static int ftdi_sio_port_probe(struct us
kref_init(&priv->kref);
mutex_init(&priv->cfg_lock);
memset(&priv->icount, 0x00, sizeof(priv->icount));
- init_waitqueue_head(&priv->delta_msr_wait);
priv->flags = ASYNC_LOW_LATENCY;
- priv->dev_gone = false;
if (quirk && quirk->port_probe)
quirk->port_probe(priv);
@@ -1908,8 +1904,7 @@ static int ftdi_sio_port_remove(struct u
dbg("%s", __func__);
- priv->dev_gone = true;
- wake_up_interruptible_all(&priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
remove_sysfs_attrs(port);
@@ -2064,7 +2059,7 @@ static int ftdi_process_packet(struct tt
if (diff_status & FTDI_RS0_RLSD)
priv->icount.dcd++;
- wake_up_interruptible_all(&priv->delta_msr_wait);
+ wake_up_interruptible(&port->delta_msr_wait);
priv->prev_status = status;
}
@@ -2467,11 +2462,15 @@ static int ftdi_ioctl(struct tty_struct
*/
case TIOCMIWAIT:
cprev = priv->icount;
- while (!priv->dev_gone) {
- interruptible_sleep_on(&priv->delta_msr_wait);
+ for (;;) {
+ 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 = priv->icount;
if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
@@ -2481,8 +2480,6 @@ static int ftdi_ioctl(struct tty_struct
}
cprev = cnow;
}
- return -EIO;
- break;
case TIOCSERGETLSR:
return get_lsr_info(port, (struct serial_struct __user *)arg);
break;
Patches currently in stable-queue which might be from jhovold@xxxxxxxxx are
queue-3.4/usb-oti6858-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-io_ti-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-ch341-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-io_edgeport-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-ftdi_sio-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-ark3116-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-pl2303-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-cypress_m8-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-ssu100-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-mct_u232-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-spcp8x5-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-ti_usb_3410_5052-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-mos7840-fix-broken-tiocmiwait.patch
queue-3.4/usb-serial-fix-hang-when-opening-port.patch
queue-3.4/usb-mos7840-fix-use-after-free-in-tiocmiwait.patch
queue-3.4/usb-serial-add-modem-status-change-wait-queue.patch
--
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