[PATCH 3.4 72/88] serial: pch_uart: fix tty-kref leak in dma-rx path

Greg Kroah-Hartman
2014-06-10T00:26:24Z

From: Johan Hovold <jhovold@gmail.com>

commit 19b85cfb190eb9980eaf416bff96aef4159a430e upstream.

Fix tty_kref leak when tty_buffer_request room fails in dma-rx path.

Note that the tty ref isn't really needed anymore, but as the leak has
always been there, fixing it before removing should makes it easier to
backport the fix.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/serial/pch_uart.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -646,11 +646,12 @@ static int dma_push_rx(struct eg20t_port
dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
size - room);
if (!room)
- return room;
+ goto out;

tty_insert_flip_string(tty, sg_virt(&priv->sg_rx), size);

port->icount.rx += room;
+out:
tty_kref_put(tty);

return room;