From 389baed01edd298c9622c6e28de5e7e250c8767d Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Wed, 21 Nov 2012 19:04:51 +0900 Subject: [PATCH] PM / devfreq: missing rcu_read_lock() added for find_device_opp() opp_get_notifier() uses find_device_opp(), which requires to held rcu_read_lock. In order to keep the notifier-header valid, we have added rcu_read_lock(). Reported-by: Kees Cook Signed-off-by: MyungJoo Ham --- drivers/devfreq/devfreq.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 45e053e..1a78ad9 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1023,11 +1023,18 @@ struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, */ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh = opp_get_notifier(dev); + struct srcu_notifier_head *nh; + int ret = 0; + rcu_read_lock(); + nh = opp_get_notifier(dev); if (IS_ERR(nh)) - return PTR_ERR(nh); - return srcu_notifier_chain_register(nh, &devfreq->nb); + ret = PTR_ERR(nh); + rcu_read_unlock(); + if (!ret) + ret = srcu_notifier_chain_register(nh, &devfreq->nb); + + return ret; } /** @@ -1042,11 +1049,18 @@ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) */ int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) { - struct srcu_notifier_head *nh = opp_get_notifier(dev); + struct srcu_notifier_head *nh; + int ret = 0; + rcu_read_lock(); + nh = opp_get_notifier(dev); if (IS_ERR(nh)) - return PTR_ERR(nh); - return srcu_notifier_chain_unregister(nh, &devfreq->nb); + ret = PTR_ERR(nh); + rcu_read_unlock(); + if (!ret) + ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); + + return ret; } MODULE_AUTHOR("MyungJoo Ham "); -- 2.7.4