tty: rocket: Remove RCPK_GET_STRUCT ioctl

If the cmd is RCPK_GET_STRUCT, copy_to_user will copy
info to user space. As info->port.ops is the address of
a constant object rocket_port_ops (assigned in init_r_port),
a kernel address leakage happens.

Remove the RCPK_GET_STRUCT ioctl.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/rocket.c

@@ -1283,10 +1283,6 @@ static int rp_ioctl(struct tty_struct *tty,
 		return -ENXIO;
 
 	switch (cmd) {
-	case RCKP_GET_STRUCT:
-		if (copy_to_user(argp, info, sizeof (struct r_port)))
-			ret = -EFAULT;
-		break;
 	case RCKP_GET_CONFIG:
 		ret = get_config(info, argp);
 		break;

drivers/tty/rocket.h

@@ -71,7 +71,6 @@ struct rocket_version {
 /*
  * Rocketport ioctls -- "RP"
  */
-#define RCKP_GET_STRUCT		0x00525001
 #define RCKP_GET_CONFIG		0x00525002
 #define RCKP_SET_CONFIG		0x00525003
 #define RCKP_GET_PORTS		0x00525004