diff options
| author | Johan Hovold <jhovold@gmail.com> | 2014-05-26 19:23:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-30 20:01:32 -0700 |
| commit | 887b3c368f744e95538a6ab0f9d91d21d933c5c4 (patch) | |
| tree | e33849a55881e642c5d55879617fec10fb4c0b45 | |
| parent | 50476eeb49caef5d03baec2ca9ca1187bb87b738 (diff) | |
USB: usb_wwan: fix write and suspend race
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@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/serial/usb_wwan.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c index e2fccbf1010c..3ae232ac76d7 100644 --- a/drivers/usb/serial/usb_wwan.c +++ b/drivers/usb/serial/usb_wwan.c @@ -647,22 +647,20 @@ EXPORT_SYMBOL(usb_wwan_release); int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) { struct usb_wwan_intf_private *intfdata = serial->private; - int b; dbg("%s entered", __func__); + 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; |