hwmon: (fschmd) Fix a memleak on multiple opens of /dev/watchdog
When /dev/watchdog gets opened a second time we return -EBUSY, but
we already have got a kref then, so we end up leaking our data struct.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org
diff --git a/drivers/hwmon/fschmd.c b/drivers/hwmon/fschmd.c
index bd0fc67..fa07282 100644
--- a/drivers/hwmon/fschmd.c
+++ b/drivers/hwmon/fschmd.c
@@ -768,6 +768,7 @@
static int watchdog_open(struct inode *inode, struct file *filp)
{
struct fschmd_data *pos, *data = NULL;
+ int watchdog_is_open;
/* We get called from drivers/char/misc.c with misc_mtx hold, and we
call misc_register() from fschmd_probe() with watchdog_data_mutex
@@ -782,10 +783,12 @@
}
}
/* Note we can never not have found data, so we don't check for this */
- kref_get(&data->kref);
+ watchdog_is_open = test_and_set_bit(0, &data->watchdog_is_open);
+ if (!watchdog_is_open)
+ kref_get(&data->kref);
mutex_unlock(&watchdog_data_mutex);
- if (test_and_set_bit(0, &data->watchdog_is_open))
+ if (watchdog_is_open)
return -EBUSY;
/* Start the watchdog */