Johan Hovold 5a345c20c1 USB: cdc-acm: 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 write_lock after determining the
device is idle but before incrementing the susp_count, thus leaving a
window where a concurrent write() can submit an urb.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>        # v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2014-05-27 15:04:08 -07:00

50 KiB

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