Commit edf786e2 authored Aug 07, 2020 by Madhuparna Bhowmik Committed by Greg Kroah-Hartman Nov 05, 2020

drivers: watchdog: rdc321x_wdt: Fix race condition bugs



[ 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>

parent 9d5fa0ad

drivers/watchdog/rdc321x_wdt.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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);

		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;