watchdog: Ensure that wdd is not dereferenced if NULL
authorGuenter Roeck <linux@roeck-us.net>
Wed, 9 Mar 2016 02:46:13 +0000 (18:46 -0800)
committerWim Van Sebroeck <wim@iguana.be>
Wed, 16 Mar 2016 20:11:50 +0000 (21:11 +0100)
commitd1ed3ba4e3d76b4ebec239c64f990c26d7935700
tree841d94b53efd656fef958538bee429f6c1c379de
parent11d7aba9ceb726d86aaaca3eb5f7d79de38989c5
watchdog: Ensure that wdd is not dereferenced if NULL

Smatch rightfully complains that wdd is dereferenced in the watchdog
release function after being checked for NULL. Also make sure that it
is not accessed outside mutex protection to avoid use-after-free problems.

Fixes: e6c71e84e4c0 ("watchdog: Introduce WDOG_HW_RUNNING flag")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/watchdog_dev.c