tty: moxa, fix refcounting in moxa_poll_port

There is missing tty_kref_put on some paths in moxa_poll_port,
although the reference is always taken. Fix it.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Reported-by: Jan 'Yenya' Kasprzak <kas@fi.muni.cz>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 8b0da97d5293..4a4cab73d0be 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -1486,11 +1486,11 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
         }
 
         if (!handle) /* nothing else to do */
-                return 0;
+                goto put;
 
         intr = readw(ip); /* port irq status */
         if (intr == 0)
-                return 0;
+                goto put;
 
         writew(0, ip); /* ACK port */
         ofsAddr = p->tableAddr;
@@ -1499,16 +1499,17 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
                                 ofsAddr + HostStat);
 
         if (!inited)
-                return 0;
+                goto put;
 
         if (tty && (intr & IntrBreak) && !I_IGNBRK(tty)) { /* BREAK */
                 tty_insert_flip_char(tty, 0, TTY_BREAK);
                 tty_schedule_flip(tty);
         }
-        tty_kref_put(tty);
 
         if (intr & IntrLine)
                 moxa_new_dcdstate(p, readb(ofsAddr + FlagStat) & DCD_state);
+put:
+        tty_kref_put(tty);
 
         return 0;
 }