3.11.10.8 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Daniel Fu <[email protected]>

commit 3b9c10e98021e1f92e6f8c7ce1778b86ba68db10 upstream.

If the current CPU has no cpuidle driver, drv will be NULL in
cpuidle_driver_ref().  Check if that is the case before trying
to bump up the driver's refcount to prevent the kernel from
crashing.

[rjw: Subject and changelog]
Signed-off-by: Daniel Fu <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Mark Brown <[email protected]>
Signed-off-by: Luis Henriques <[email protected]>
---
 drivers/cpuidle/driver.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c
index 3ac499d..6e11701 100644
--- a/drivers/cpuidle/driver.c
+++ b/drivers/cpuidle/driver.c
@@ -331,7 +331,8 @@ struct cpuidle_driver *cpuidle_driver_ref(void)
        spin_lock(&cpuidle_driver_lock);
 
        drv = cpuidle_get_driver();
-       drv->refcnt++;
+       if (drv)
+               drv->refcnt++;
 
        spin_unlock(&cpuidle_driver_lock);
        return drv;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to