| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 27/86] drivers: watchdog: rdc321x_wdt: Fix race condition bugs | Date | Mon, 9 Nov 2020 13:54:34 +0100 |
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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; -- 2.27.0
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