drivers: watchdog: rdc321x_wdt: Fix race condition bugs
authorMadhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Fri, 7 Aug 2020 11:29:02 +0000 (16:59 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 5 Nov 2020 10:51:27 +0000 (11:51 +0100)
commitd9371ef33695b2a71ba3594872fa51af87e18f8c
tree081487b8beba7ccfe1c55f455e8477a831eb90b9
parenta33ce4dc05b38763d508d8697fb4982cdc394223
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>
drivers/watchdog/rdc321x_wdt.c