| Message ID | 20230303213716.2123717-2-u.kleine-koenig@pengutronix.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | watchdog: Convert to platform remove callback returning void | expand |
Hi Uwe, On 3/3/23 13:36, Uwe Kleine-König wrote: > Returning early in a platform driver's remove callback is wrong. In this > case the watchdog device is never removed although it's parent is gone > which likely can trigger a use-after-free in sysfs. Also the two used > clocks will never be disabled. > > Instead only warn if s3c2410wdt_enable() fails and cleanup. Note that > returning 0 is the right thing to do then to suppress another warning > message by the driver core. > > Fixes: 4f1f653a68d6 ("watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register") > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/watchdog/s3c2410_wdt.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c > index 200ba236a72e..cf104a844a43 100644 > --- a/drivers/watchdog/s3c2410_wdt.c > +++ b/drivers/watchdog/s3c2410_wdt.c > @@ -782,7 +782,8 @@ static int s3c2410wdt_remove(struct platform_device *dev) > > ret = s3c2410wdt_enable(wdt, false); > if (ret < 0) > - return ret; > + dev_warn(&dev->dev, > + "Failed to disable watchdog (%pe)\n", ERR_PTR(ret)); > > watchdog_unregister_device(&wdt->wdt_device); > I sent out two patches a minute ago which should make this patch as well as the use of the remove_new callback unnecessary. Guenter
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index 200ba236a72e..cf104a844a43 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -782,7 +782,8 @@ static int s3c2410wdt_remove(struct platform_device *dev) ret = s3c2410wdt_enable(wdt, false); if (ret < 0) - return ret; + dev_warn(&dev->dev, + "Failed to disable watchdog (%pe)\n", ERR_PTR(ret)); watchdog_unregister_device(&wdt->wdt_device);
Returning early in a platform driver's remove callback is wrong. In this case the watchdog device is never removed although it's parent is gone which likely can trigger a use-after-free in sysfs. Also the two used clocks will never be disabled. Instead only warn if s3c2410wdt_enable() fails and cleanup. Note that returning 0 is the right thing to do then to suppress another warning message by the driver core. Fixes: 4f1f653a68d6 ("watchdog: s3c2410_wdt: use syscon regmap interface to configure pmu register") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/watchdog/s3c2410_wdt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)