USB: serial: ftdi_sio: fix modem-status error handling
authorJohan Hovold <johan@kernel.org>
Thu, 12 Jan 2017 13:56:11 +0000 (14:56 +0100)
committerJohan Hovold <johan@kernel.org>
Mon, 16 Jan 2017 15:38:55 +0000 (16:38 +0100)
commit427c3a95e3e29e65f59d99aaf320d7506f3eed57
treeef6ec9ae9040988324add87baaf33ecbde1e1302
parentb631433b175f1002a31020e09bbfc2e5caecf290
USB: serial: ftdi_sio: fix modem-status error handling

Make sure to detect short responses when fetching the modem status in
order to avoid parsing uninitialised buffer data and having bits of it
leak to user space.

Note that we still allow for short 1-byte responses.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
drivers/usb/serial/ftdi_sio.c