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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Sasha Levin <sashal@kernel.org>,
	linux-watchdog@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 24/30] drivers: watchdog: rdc321x_wdt: Fix race condition bugs
Date: Mon, 26 Oct 2020 20:10:38 -0400	[thread overview]
Message-ID: <20201027001044.1027349-24-sashal@kernel.org> (raw)
In-Reply-To: <20201027001044.1027349-1-sashal@kernel.org>

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

[ Upstream commit 4b2e7f99cdd314263c9d172bc17193b8b6bba463 ]

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>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20200807112902.28764-1-madhuparnabhowmik10@gmail.com
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/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 47a8f1b1087d4..4568af9a165be 100644
--- a/drivers/watchdog/rdc321x_wdt.c
+++ b/drivers/watchdog/rdc321x_wdt.c
@@ -244,6 +244,8 @@ 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) {
@@ -258,14 +260,11 @@ 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);
 
 	setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
 
-	rdc321x_wdt_device.default_ticks = ticks;
-
 	dev_info(&pdev->dev, "watchdog init success\n");
 
 	return 0;
-- 
2.25.1


           reply	other threads:[~2020-10-27  0:15 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20201027001044.1027349-1-sashal@kernel.org>]

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