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: [PATCH] cdc-acm: fix race between reset and control messaging
Git-commit: 9397940ed812b942c520e0c25ed4b2c64d57e8b9
Patch-mainline: v4.19
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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