tty: Fix USB kref leak

The sysrq code acquired a kref leak. Fix it by passing the tty separately
from the caller (thus effectively using the callers kref which all the
callers hold anyway)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 6 insertions, 5 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 3dc3768ca71..5f08702f672 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2121,7 +2121,7 @@ static void ftdi_process_read(struct work_struct *work)
                                 /* Note that the error flag is duplicated for
                                    every character received since we don't know
                                    which character it applied to */
-                                if (!usb_serial_handle_sysrq_char(port,
+                                if (!usb_serial_handle_sysrq_char(tty, port,
                                                 data[packet_offset + i]))
                                         tty_insert_flip_char(tty,
                                                 data[packet_offset + i],
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 3d8dc5671be..ce57f6a32bd 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -432,7 +432,7 @@ static void flush_and_resubmit_read_urb(struct usb_serial_port *port)
         else {
                 /* Push data to tty */
                 for (i = 0; i < urb->actual_length; i++, ch++) {
-                        if (!usb_serial_handle_sysrq_char(port, *ch))
+                        if (!usb_serial_handle_sysrq_char(tty, port, *ch))
                                 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
                 }
         }
@@ -534,11 +534,12 @@ void usb_serial_generic_unthrottle(struct tty_struct *tty)
         }
 }
 
-int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
+int usb_serial_handle_sysrq_char(struct tty_struct *tty,
+                        struct usb_serial_port *port, unsigned int ch)
 {
         if (port->sysrq && port->console) {
                 if (ch && time_before(jiffies, port->sysrq)) {
-                        handle_sysrq(ch, tty_port_tty_get(&port->port));
+                        handle_sysrq(ch, tty);
                         port->sysrq = 0;
                         return 1;
                 }
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index ec6c132a25b..8835802067f 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -1038,7 +1038,7 @@ static void pl2303_read_bulk_callback(struct urb *urb)
                 if (line_status & UART_OVERRUN_ERROR)
                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
                 for (i = 0; i < urb->actual_length; ++i)
-                        if (!usb_serial_handle_sysrq_char(port, data[i]))
+                        if (!usb_serial_handle_sysrq_char(tty, port, data[i]))
                                 tty_insert_flip_char(tty, data[i], tty_flag);
                 tty_flip_buffer_push(tty);
         }