USB: usb_wwan: fix write and suspend race
authorJohan Hovold <jhovold@gmail.com>
Mon, 26 May 2014 17:23:15 +0000 (19:23 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 27 May 2014 22:04:05 +0000 (15:04 -0700)
commit170fad9e22df0063eba0701adb966786d7a4ec5a
tree3437346642f8e76f5c39298106e576a0f7c8dfa6
parentd9e93c08d8d985e5ef89436ebc9f4aad7e31559f
USB: usb_wwan: fix write and suspend race

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")

Cc: <stable@vger.kernel.org> # v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/serial/usb_wwan.c