[PATCH AUTOSEL 6.1 2/9] watchdog: menz069_wdt: fix watchdog initialisation

Sasha Levin
2023-05-11T19:40:48Z

From: Johannes Thumshirn <jth@kernel.org>

[ Upstream commit 87b22656ca6a896d0378e9e60ffccb0c82f48b08 ]

Doing a 'cat /dev/watchdog0' with menz069_wdt as watchdog0 will result in
a NULL pointer dereference.

This happens because we're passing the wrong pointer to
watchdog_register_device(). Fix this by getting rid of the static
watchdog_device structure and use the one embedded into the driver's
per-instance private data.

Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230418172531.177349-2-jth@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/watchdog/menz69_wdt.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/watchdog/menz69_wdt.c b/drivers/watchdog/menz69_wdt.c
index 8973f98bc6a56..bca0938f3429f 100644
--- a/drivers/watchdog/menz69_wdt.c
+++ b/drivers/watchdog/menz69_wdt.c
@@ -98,14 +98,6 @@ static const struct watchdog_ops men_z069_ops = {
.set_timeout = men_z069_wdt_set_timeout,
};

-static struct watchdog_device men_z069_wdt = {
- .info = &men_z069_info,
- .ops = &men_z069_ops,
- .timeout = MEN_Z069_DEFAULT_TIMEOUT,
- .min_timeout = 1,
- .max_timeout = MEN_Z069_WDT_COUNTER_MAX / MEN_Z069_TIMER_FREQ,
-};
-
static int men_z069_probe(struct mcb_device *dev,
const struct mcb_device_id *id)
{
@@ -125,15 +117,19 @@ static int men_z069_probe(struct mcb_device *dev,
goto release_mem;

drv->mem = mem;
+ drv->wdt.info = &men_z069_info;
+ drv->wdt.ops = &men_z069_ops;
+ drv->wdt.timeout = MEN_Z069_DEFAULT_TIMEOUT;
+ drv->wdt.min_timeout = 1;
+ drv->wdt.max_timeout = MEN_Z069_WDT_COUNTER_MAX / MEN_Z069_TIMER_FREQ;

- drv->wdt = men_z069_wdt;
watchdog_init_timeout(&drv->wdt, 0, &dev->dev);
watchdog_set_nowayout(&drv->wdt, nowayout);
watchdog_set_drvdata(&drv->wdt, drv);
drv->wdt.parent = &dev->dev;
mcb_set_drvdata(dev, drv);

- return watchdog_register_device(&men_z069_wdt);
+ return watchdog_register_device(&drv->wdt);

release_mem:
mcb_release_mem(mem);
--
2.39.2