[PATCH] Input: byd - synchronize timer deletion before freeing private data

[Linmao Li]

byd_disconnect() uses timer_delete() before freeing the driver's private
data.  This does not wait for a running byd_clear_touch() callback, which
dereferences the private data and its psmouse pointer.  A callback racing
with disconnect can therefore access the private data after it has been
freed.

Use timer_delete_sync() to wait for any running callback before releasing
the private data.

Fixes: 2d5f5611dd0d ("Input: byd - enable absolute mode")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Linmao Li <lilinmao@xxxxxxxxxx>
---
 drivers/input/mouse/byd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index f5770a3af2f1..7a69724c1ac6 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -423,7 +423,7 @@ static void byd_disconnect(struct psmouse *psmouse)
 	struct byd_data *priv = psmouse->private;
 
 	if (priv) {
-		timer_delete(&priv->timer);
+		timer_delete_sync(&priv->timer);
 		kfree(psmouse->private);
 		psmouse->private = NULL;
 	}
-- 
2.25.1