usbip: fix stub_dev to check for stream socket

commit 47ccc8fc2c9c94558b27b6f9e2582df32d29e6e8 upstream.

Fix usbip_sockfd_store() to validate the passed in file descriptor is
a stream socket. If the file descriptor passed was a SOCK_DGRAM socket,
sock_recvmsg() can't detect end of stream.

Cc: stable@vger.kernel.org
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/e942d2bd03afb8e8552bd2a5d84e18d17670d521.1615171203.git.skhan@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>