Tools: hv: verify origin of netlink connector message

The SuSE security team suggested to use recvfrom instead of recv to be
certain that the connector message is originated from kernel.

CVE-2012-2669

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Marcus Meissner <meissner@suse.de>
Signed-off-by: Sebastian Krahmer <krahmer@suse.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
static void kvp_release_lock(int pool)
{
	struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0};
	fl.l_pid = getpid();

	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {
		perror("fcntl");
		syslog(LOG_ERR, "Failed to release the lock pool: %d", pool);
		exit(-1);
	}
}

static void kvp_release_lock(int pool)
{
	struct flock fl = {F_UNLCK, SEEK_SET, 0, 0, 0};
	fl.l_pid = getpid();

	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {
		perror("fcntl");
		syslog(LOG_ERR, "Failed to release the lock pool: %d", pool);
		exit(-1);
	}
}
