From d692170037c0338b31dac5ac4722c1360a4b5257 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Sun, 16 Dec 2012 13:23:17 +0200 Subject: watchdog: mei: avoid oops in watchdog unregister code path With commit c7d3df3 "mei: use internal watchdog device registration tracking" will crash the kernel on shutdown path on systems where ME watchdog is not present. Since the watchdog was never initialized in such case the WDOG_UNREGISTERED bit is never set and the system crashes on access to uninitialized variables down the path. To solve the issue we query for NULL on watchdog driver driver_data to check whether the device is registered. This is handled in the driver and doesn't depend on watchdog core internals. Cc: Borislav Petkov Cc: Wanlong Gao Signed-off-by: Jerry Snitselaar Signed-off-by: Tomas Winkler Signed-off-by: Wim Van Sebroeck --- drivers/misc/mei/wd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c index 636409f9667f..9299a8c29a6f 100644 --- a/drivers/misc/mei/wd.c +++ b/drivers/misc/mei/wd.c @@ -370,7 +370,7 @@ void mei_watchdog_register(struct mei_device *dev) void mei_watchdog_unregister(struct mei_device *dev) { - if (test_bit(WDOG_UNREGISTERED, &amt_wd_dev.status)) + if (watchdog_get_drvdata(&amt_wd_dev) == NULL) return; watchdog_set_drvdata(&amt_wd_dev, NULL); -- cgit v1.2.3-55-g7522