[PATCHv2 3/3] watchdog: sama5d4: fix NULL deref in irq handler

[Rosen Penev]

Move platform_set_drvdata() before devm_request_irq() so that the
interrupt handler can safely dereference the driver data via
platform_get_drvdata().  An interrupt on the shared System IRQ line
(SAM9X60/SAM9X7) could fire between request_irq and the late
platform_set_drvdata() call, causing the handler to dereference NULL.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp at gmail.com>
---
 drivers/watchdog/sama5d4_wdt.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index 2536e2f2ab32..7cd6f35c8e21 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -268,6 +268,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 						: AT91_WDT_WDDIS;
 
 	watchdog_set_drvdata(wdd, wdt);
+	platform_set_drvdata(pdev, wdt);
 
 	regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(regs))
@@ -319,8 +320,6 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	platform_set_drvdata(pdev, wdt);
-
 	dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n",
 		 wdd->timeout, nowayout);
 
-- 
2.54.0