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From: madhuparnabhowmik10@gmail.com
To: wim@linux-watchdog.org, linux@roeck-us.net
Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org,
	andrianov@ispras.ru, ldv-project@linuxtesting.org,
	Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Subject: [PATCH] drivers: watchdog: rdc321x_wdt: Fix race condition bugs
Date: Fri,  7 Aug 2020 16:59:02 +0530	[thread overview]
Message-ID: <20200807112902.28764-1-madhuparnabhowmik10@gmail.com> (raw)

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

In rdc321x_wdt_probe(), rdc321x_wdt_device.queue is initialized
after misc_register(), hence if ioctl is called before its
initialization which can call rdc321x_wdt_start() function,
it will see an uninitialized value of rdc321x_wdt_device.queue,
hence initialize it before misc_register().
Also, rdc321x_wdt_device.default_ticks is accessed in reset()
function called from write callback, thus initialize it before
misc_register().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
---
 drivers/watchdog/rdc321x_wdt.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/rdc321x_wdt.c b/drivers/watchdog/rdc321x_wdt.c
index 57187efeb86f..f0c94ea51c3e 100644
--- a/drivers/watchdog/rdc321x_wdt.c
+++ b/drivers/watchdog/rdc321x_wdt.c
@@ -231,6 +231,8 @@ static int rdc321x_wdt_probe(struct platform_device *pdev)
 
 	rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
 	rdc321x_wdt_device.base_reg = r->start;
+	rdc321x_wdt_device.queue = 0;
+	rdc321x_wdt_device.default_ticks = ticks;
 
 	err = misc_register(&rdc321x_wdt_misc);
 	if (err < 0) {
@@ -245,14 +247,11 @@ static int rdc321x_wdt_probe(struct platform_device *pdev)
 				rdc321x_wdt_device.base_reg, RDC_WDT_RST);
 
 	init_completion(&rdc321x_wdt_device.stop);
-	rdc321x_wdt_device.queue = 0;
 
 	clear_bit(0, &rdc321x_wdt_device.inuse);
 
 	timer_setup(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
 
-	rdc321x_wdt_device.default_ticks = ticks;
-
 	dev_info(&pdev->dev, "watchdog init success\n");
 
 	return 0;
-- 
2.17.1


             reply	other threads:[~2020-08-07 11:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-07 11:29 madhuparnabhowmik10 [this message]
2020-08-07 16:21 ` [PATCH] drivers: watchdog: rdc321x_wdt: Fix race condition bugs Guenter Roeck
2020-08-07 18:08   ` Florian Fainelli
2020-08-07 18:19     ` Guenter Roeck
2020-08-07 19:08     ` Guenter Roeck
2020-08-07 20:09       ` Florian Fainelli
2020-08-07 23:23         ` Guenter Roeck
2020-08-08  0:41           ` Florian Fainelli
2020-08-08  4:58             ` Guenter Roeck
2020-08-07 18:30   ` [ldv-project] " Evgeny Novikov
2020-08-07 19:00     ` Guenter Roeck

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