| Message ID | 20190119050256.22520-1-tiny.windzz@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | PM / devfreq: fix mem leak and missing check of return value in devfreq_add_device() | expand |
Hi Yangtao, 2019년 1월 19일 (토) 오후 2:03, Yangtao Li <tiny.windzz@gmail.com>님이 작성: > > 'devfreq' is malloced in devfreq_add_device() and should be freed in > the error handling cases, otherwise it will cause memory leak. > > devm_kzalloc() could fail, so insert a check of its return value. And > if it fails, returns -ENOMEM. > > Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> > --- > drivers/devfreq/devfreq.c | 33 ++++++++++++++++++++++----------- > 1 file changed, 22 insertions(+), 11 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0ae3de76833b..fe6c157cb7e0 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -651,7 +651,7 @@ struct devfreq *devfreq_add_device(struct device *dev, > mutex_unlock(&devfreq->lock); > err = set_freq_table(devfreq); > if (err < 0) > - goto err_out; > + goto err_dev; > mutex_lock(&devfreq->lock); > } > > @@ -683,16 +683,27 @@ struct devfreq *devfreq_add_device(struct device *dev, > goto err_out; > } > > - devfreq->trans_table = > - devm_kzalloc(&devfreq->dev, > - array3_size(sizeof(unsigned int), > - devfreq->profile->max_state, > - devfreq->profile->max_state), > - GFP_KERNEL); > + devfreq->trans_table = devm_kzalloc(&devfreq->dev, > + array3_size(sizeof(unsigned int), > + devfreq->profile->max_state, > + devfreq->profile->max_state), > + GFP_KERNEL); The above 10 ten lines are not related to the memory leak for this patch. If you want to fix the indentation, you have to make it separately. > + if (!devfreq->trans_table) { > + mutex_unlock(&devfreq->lock); > + err = -ENOMEM; > + goto err_devfreq; > + } > + > devfreq->time_in_state = devm_kcalloc(&devfreq->dev, > - devfreq->profile->max_state, > - sizeof(unsigned long), > - GFP_KERNEL); > + devfreq->profile->max_state, > + sizeof(unsigned long), > + GFP_KERNEL); ditto. The above 6 ten lines are not related to the memory leak for this patch. If you want to fix the indentation, you have to make it separately. > + if (!devfreq->time_in_state) { > + mutex_unlock(&devfreq->lock); > + err = -ENOMEM; > + goto err_devfreq; > + } > + > devfreq->last_stat_updated = jiffies; > > srcu_init_notifier_head(&devfreq->transition_notifier_list); > @@ -726,7 +737,7 @@ struct devfreq *devfreq_add_device(struct device *dev, > > err_init: > mutex_unlock(&devfreq_list_lock); > - > +err_devfreq: > devfreq_remove_device(devfreq); > devfreq = NULL; > err_dev: Also, you better to add following codes to free the memory of 'devfreq->trans_table' and 'devfreq->time_in_state' because this patch handles the memory leak of 'trans_table' and 'time_in_state' variables. diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 0ae3de7..945f5f1 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -593,6 +593,9 @@ static void devfreq_dev_release(struct device *dev) devfreq->profile->exit(devfreq->dev.parent); mutex_destroy(&devfreq->lock); + kfree(devfreq->trans_table); + kfree(devfreq->time_in_state); kfree(devfreq); }
> Also, you better to add following codes to free the memory of > 'devfreq->trans_table' and 'devfreq->time_in_state' because this patch > handles the memory leak of 'trans_table' and 'time_in_state' > variables. Hi Chanwoo: Isn't that the mem requested by the devm_ API automatically freed when the device is detached? So we don't need to pay attention to free these mem. Thanks， Yangtao > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 0ae3de7..945f5f1 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -593,6 +593,9 @@ static void devfreq_dev_release(struct device *dev) > devfreq->profile->exit(devfreq->dev.parent); > > mutex_destroy(&devfreq->lock); > + kfree(devfreq->trans_table); > + kfree(devfreq->time_in_state); > kfree(devfreq); > } > > -- > Best Regards, > Chanwoo Choi > Samsung Electronics
> 'devfreq' is malloced in devfreq_add_device() and should be freed in > the error handling cases, otherwise it will cause memory leak. > > devm_kzalloc() could fail, so insert a check of its return value. And > if it fails, returns -ENOMEM. > > Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Dear Yangtao, Could you please make your patch without indentation style changes? The label, "err_devfreq", would fit more if it's renamed "err_kzalloc". Cheers, MyungJoo.
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 0ae3de76833b..fe6c157cb7e0 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -651,7 +651,7 @@ struct devfreq *devfreq_add_device(struct device *dev, mutex_unlock(&devfreq->lock); err = set_freq_table(devfreq); if (err < 0) - goto err_out; + goto err_dev; mutex_lock(&devfreq->lock); } @@ -683,16 +683,27 @@ struct devfreq *devfreq_add_device(struct device *dev, goto err_out; } - devfreq->trans_table = - devm_kzalloc(&devfreq->dev, - array3_size(sizeof(unsigned int), - devfreq->profile->max_state, - devfreq->profile->max_state), - GFP_KERNEL); + devfreq->trans_table = devm_kzalloc(&devfreq->dev, + array3_size(sizeof(unsigned int), + devfreq->profile->max_state, + devfreq->profile->max_state), + GFP_KERNEL); + if (!devfreq->trans_table) { + mutex_unlock(&devfreq->lock); + err = -ENOMEM; + goto err_devfreq; + } + devfreq->time_in_state = devm_kcalloc(&devfreq->dev, - devfreq->profile->max_state, - sizeof(unsigned long), - GFP_KERNEL); + devfreq->profile->max_state, + sizeof(unsigned long), + GFP_KERNEL); + if (!devfreq->time_in_state) { + mutex_unlock(&devfreq->lock); + err = -ENOMEM; + goto err_devfreq; + } + devfreq->last_stat_updated = jiffies; srcu_init_notifier_head(&devfreq->transition_notifier_list); @@ -726,7 +737,7 @@ struct devfreq *devfreq_add_device(struct device *dev, err_init: mutex_unlock(&devfreq_list_lock); - +err_devfreq: devfreq_remove_device(devfreq); devfreq = NULL; err_dev:
'devfreq' is malloced in devfreq_add_device() and should be freed in the error handling cases, otherwise it will cause memory leak. devm_kzalloc() could fail, so insert a check of its return value. And if it fails, returns -ENOMEM. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> --- drivers/devfreq/devfreq.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-)