Patch "USB: cdc-wdm: fix race between interrupt handler and tasklet" has been added to the 3.11-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

    USB: cdc-wdm: fix race between interrupt handler and tasklet

to the 3.11-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-cdc-wdm-fix-race-between-interrupt-handler-and-tasklet.patch
and it can be found in the queue-3.11 subdirectory.

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


>From 6dd433e6cf2475ce8abec1b467720858c24450eb Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@xxxxxxx>
Date: Tue, 6 Aug 2013 14:22:59 +0200
Subject: USB: cdc-wdm: fix race between interrupt handler and tasklet

From: Oliver Neukum <oneukum@xxxxxxx>

commit 6dd433e6cf2475ce8abec1b467720858c24450eb upstream.

Both could want to submit the same URB. Some checks of the flag
intended to prevent that were missing.

Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/class/cdc-wdm.c |   13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -209,6 +209,7 @@ skip_error:
 static void wdm_int_callback(struct urb *urb)
 {
 	int rv = 0;
+	int responding;
 	int status = urb->status;
 	struct wdm_device *desc;
 	struct usb_cdc_notification *dr;
@@ -262,8 +263,8 @@ static void wdm_int_callback(struct urb
 
 	spin_lock(&desc->iuspin);
 	clear_bit(WDM_READ, &desc->flags);
-	set_bit(WDM_RESPONDING, &desc->flags);
-	if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+	responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
+	if (!responding && !test_bit(WDM_DISCONNECTING, &desc->flags)
 		&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
 		rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 		dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
@@ -685,16 +686,20 @@ static void wdm_rxwork(struct work_struc
 {
 	struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 	unsigned long flags;
-	int rv;
+	int rv = 0;
+	int responding;
 
 	spin_lock_irqsave(&desc->iuspin, flags);
 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 		spin_unlock_irqrestore(&desc->iuspin, flags);
 	} else {
+		responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
 		spin_unlock_irqrestore(&desc->iuspin, flags);
-		rv = usb_submit_urb(desc->response, GFP_KERNEL);
+		if (!responding)
+			rv = usb_submit_urb(desc->response, GFP_KERNEL);
 		if (rv < 0 && rv != -EPERM) {
 			spin_lock_irqsave(&desc->iuspin, flags);
+			clear_bit(WDM_RESPONDING, &desc->flags);
 			if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 				schedule_work(&desc->rxwork);
 			spin_unlock_irqrestore(&desc->iuspin, flags);


Patches currently in stable-queue which might be from oneukum@xxxxxxx are

queue-3.11/usb-cdc-wdm-fix-race-between-interrupt-handler-and-tasklet.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




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]