Patch "USB: serial: cp210x: fix tiocmget error handling" has been added to the 4.4-stable tree

Patch "USB: serial: cp210x: fix tiocmget error handling" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: serial: cp210x: fix tiocmget error handling

to the 4.4-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-serial-cp210x-fix-tiocmget-error-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From de24e0a108bc48062e1c7acaa97014bce32a919f Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 19 Oct 2016 15:45:07 +0200
Subject: USB: serial: cp210x: fix tiocmget error handling

From: Johan Hovold <johan@kernel.org>

commit de24e0a108bc48062e1c7acaa97014bce32a919f upstream.

The current tiocmget implementation would fail to report errors up the
stack and instead leaked a few bits from the stack as a mask of
modem-status flags.

Fixes: 39a66b8d22a3 ("[PATCH] USB: CP2101 Add support for flow control")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/serial/cp210x.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -845,7 +845,9 @@ static int cp210x_tiocmget(struct tty_st
 	unsigned int control;
 	int result;
 
-	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
+	result = cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
+	if (result)
+		return result;
 
 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)


Patches currently in stable-queue which might be from johan@kernel.org are

queue-4.4/usb-serial-cp210x-fix-tiocmget-error-handling.patch
queue-4.4/usb-serial-ftdi_sio-add-support-for-infineon-triboard-tc2x7.patch
queue-4.4/usb-serial-fix-potential-null-dereference-at-probe.patch