[PATCH] watchdog: mena21_wdt: Fix possible NULL pointer dereference

[PATCH] watchdog: mena21_wdt: Fix possible NULL pointer dereference

[Johannes Thumshirn]

In a21_wdt_remove() we do a watchdog_unregister_device() on struct
a21_wdt_drv->wdt but never assign it.

Also move the dev_set_drvdata() call in front of the watchdog_register_device()
call, so it doesn't look like an error.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/watchdog/mena21_wdt.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/mena21_wdt.c b/drivers/watchdog/mena21_wdt.c
index 96dbba9..d193a5e 100644
--- a/drivers/watchdog/mena21_wdt.c
+++ b/drivers/watchdog/mena21_wdt.c
@@ -208,14 +208,15 @@ static int a21_wdt_probe(struct platform_device *pdev)
 	else if (reset == 7)
 		a21_wdt.bootstatus |= WDIOF_EXTERN2;
 
+	drv->wdt = a21_wdt;
+	dev_set_drvdata(&pdev->dev, drv);
+
 	ret = watchdog_register_device(&a21_wdt);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot register watchdog device\n");
 		goto err_register_wd;
 	}
 
-	dev_set_drvdata(&pdev->dev, drv);
-
 	dev_info(&pdev->dev, "MEN A21 watchdog timer driver enabled\n");
 
 	return 0;
-- 
2.4.1

Re: [PATCH] watchdog: mena21_wdt: Fix possible NULL pointer dereference

[Guenter Roeck]

On 06/02/2015 03:25 AM, Johannes Thumshirn wrote:
> In a21_wdt_remove() we do a watchdog_unregister_device() on struct
> a21_wdt_drv->wdt but never assign it.
>
> Also move the dev_set_drvdata() call in front of the watchdog_register_device()
> call, so it doesn't look like an error.
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>

Good catch.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Guenter

Re: [PATCH] watchdog: mena21_wdt: Fix possible NULL pointer dereference

[Johannes Thumshirn]

On Tue, Jun 02, 2015 at 06:44:48AM -0700, Guenter Roeck wrote:
> On 06/02/2015 03:25 AM, Johannes Thumshirn wrote:
> >In a21_wdt_remove() we do a watchdog_unregister_device() on struct
> >a21_wdt_drv->wdt but never assign it.
> >
> >Also move the dev_set_drvdata() call in front of the watchdog_register_device()
> >call, so it doesn't look like an error.
> >
> >Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> 
> Good catch.
> 
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> 
> Guenter
> 

Hi Wim,

Any objections to this one? Do you intent to take it for 4.2?

Thanks,
	Johannes

-- 
Johannes Thumshirn                                       Storage
jthumshirn@suse.de                             +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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