This is a note to let you know that I've just added the patch titled
USB: usb_wwan: fix write and suspend race
to the 3.10-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-usb_wwan-fix-write-and-suspend-race.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 170fad9e22df0063eba0701adb966786d7a4ec5a Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@xxxxxxxxx>
Date: Mon, 26 May 2014 19:23:15 +0200
Subject: USB: usb_wwan: fix write and suspend race
From: Johan Hovold <jhovold@xxxxxxxxx>
commit 170fad9e22df0063eba0701adb966786d7a4ec5a upstream.
Fix race between write() and suspend() which could lead to writes being
dropped (or I/O while suspended) if the device is runtime suspended
while a write request is being processed.
Specifically, suspend() releases the susp_lock after determining the
device is idle but before setting the suspended flag, thus leaving a
window where a concurrent write() can submit an urb.
Fixes: 383cedc3bb43 ("USB: serial: full autosuspend support for the
option driver")
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/usb_wwan.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -583,20 +583,17 @@ static void stop_read_write_urbs(struct
int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
{
struct usb_wwan_intf_private *intfdata = serial->private;
- int b;
+ spin_lock_irq(&intfdata->susp_lock);
if (PMSG_IS_AUTO(message)) {
- spin_lock_irq(&intfdata->susp_lock);
- b = intfdata->in_flight;
- spin_unlock_irq(&intfdata->susp_lock);
-
- if (b)
+ if (intfdata->in_flight) {
+ spin_unlock_irq(&intfdata->susp_lock);
return -EBUSY;
+ }
}
-
- spin_lock_irq(&intfdata->susp_lock);
intfdata->suspended = 1;
spin_unlock_irq(&intfdata->susp_lock);
+
stop_read_write_urbs(serial);
return 0;
Patches currently in stable-queue which might be from jhovold@xxxxxxxxx are
queue-3.10/usb-usb_wwan-fix-urb-leak-at-shutdown.patch
queue-3.10/usb-option-fix-runtime-pm-handling.patch
queue-3.10/net-cpsw-fix-null-dereference-at-probe.patch
queue-3.10/usb-usb_wwan-fix-write-and-suspend-race.patch
queue-3.10/usb-usb_wwan-fix-race-between-write-and-resume.patch
queue-3.10/usb-usb_wwan-fix-urb-leak-in-write-error-path.patch
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