patch "cdc-acm: fix race between reset and control messaging" added to usb-linus

patch "cdc-acm: fix race between reset and control messaging" added to usb-linus

[gregkh]

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

    cdc-acm: fix race between reset and control messaging

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 9397940ed812b942c520e0c25ed4b2c64d57e8b9 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Thu, 4 Oct 2018 15:49:06 +0200
Subject: cdc-acm: fix race between reset and control messaging

If a device splits up a control message and a reset() happens
between the parts, the message is lost and already recieved parts
must be dropped.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: 1aba579f3cf51 ("cdc-acm: handle read pipe errors")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/class/cdc-acm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index bc03b0a690b4..1833912f7f5f 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1642,6 +1642,7 @@ static int acm_pre_reset(struct usb_interface *intf)
 	struct acm *acm = usb_get_intfdata(intf);
 
 	clear_bit(EVENT_RX_STALL, &acm->flags);
+	acm->nb_index = 0; /* pending control transfers are lost */
 
 	return 0;
 }
-- 
2.19.1