[PATCH v2 15/15] PM / devfreq: rk3399_dmc: Avoid static (reused) profile

From: Brian Norris
Date: Thu Jan 27 2022 - 18:09:18 EST


This static struct can get reused if the device gets removed/reprobed,
and that causes use-after-free in its ->freq_table.

Let's just move the struct to our dynamic allocation.

Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
---

Changes in v2:
- New patch

drivers/devfreq/rk3399_dmc.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c
index 9615658d04ae..e494d1497d60 100644
--- a/drivers/devfreq/rk3399_dmc.c
+++ b/drivers/devfreq/rk3399_dmc.c
@@ -38,6 +38,7 @@
struct rk3399_dmcfreq {
struct device *dev;
struct devfreq *devfreq;
+ struct devfreq_dev_profile profile;
struct devfreq_simple_ondemand_data ondemand_data;
struct clk *dmc_clk;
struct devfreq_event_dev *edev;
@@ -228,13 +229,6 @@ static int rk3399_dmcfreq_get_cur_freq(struct device *dev, unsigned long *freq)
return 0;
}

-static struct devfreq_dev_profile rk3399_devfreq_dmc_profile = {
- .polling_ms = 200,
- .target = rk3399_dmcfreq_target,
- .get_dev_status = rk3399_dmcfreq_get_dev_status,
- .get_cur_freq = rk3399_dmcfreq_get_cur_freq,
-};
-
static __maybe_unused int rk3399_dmcfreq_suspend(struct device *dev)
{
struct rk3399_dmcfreq *dmcfreq = dev_get_drvdata(dev);
@@ -422,10 +416,16 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
data->volt = dev_pm_opp_get_voltage(opp);
dev_pm_opp_put(opp);

- rk3399_devfreq_dmc_profile.initial_freq = data->rate;
+ data->profile = (struct devfreq_dev_profile) {
+ .polling_ms = 200,
+ .target = rk3399_dmcfreq_target,
+ .get_dev_status = rk3399_dmcfreq_get_dev_status,
+ .get_cur_freq = rk3399_dmcfreq_get_cur_freq,
+ .initial_freq = data->rate,
+ };

data->devfreq = devm_devfreq_add_device(dev,
- &rk3399_devfreq_dmc_profile,
+ &data->profile,
DEVFREQ_GOV_SIMPLE_ONDEMAND,
&data->ondemand_data);
if (IS_ERR(data->devfreq)) {
--
2.35.0.rc0.227.g00780c9af4-goog