This is a note to let you know that I've just added the patch titled
USB: mos7840: 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 a14430db686b8e459e1cf070a6ecf391515c9ab9 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@xxxxxxxxx>
Date: Tue, 19 Mar 2013 09:21:20 +0100
Subject: 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 <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 1b83b01..b8051fa 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 &&
--
1.8.0.rc0.18.gf84667d
--
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