| Message ID | 1548755757-79270-1-git-send-email-phil@raspberrypi.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Commit | 35122495a8c6683e863acf7b05a7036b2be64c7a |
| Headers | show |
| Series | [resend] thermal: bcm2835: Fix crash in bcm2835_thermal_debugfs | expand |
Phil Elwell <phil@raspberrypi.org> writes: > "cat /sys/kernel/debug/bcm2835_thermal/regset" causes a NULL pointer > dereference in bcm2835_thermal_debugfs. The driver makes use of the > implementation details of the thermal framework to retrieve a pointer > to its private data from a struct thermal_zone_device, and gets it > wrong - leading to the crash. Instead, store its private data as the > drvdata and retrieve the thermal_zone_device pointer from it. > > Fixes: bcb7dd9ef206 ("thermal: bcm2835: add thermal driver for bcm2835 SoC") > > Signed-off-by: Phil Elwell <phil@raspberrypi.org> Acked-by: Eric Anholt <eric@anholt.net> From the thread that missed Ccing the maintainers there was also: Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
diff --git a/drivers/thermal/broadcom/bcm2835_thermal.c b/drivers/thermal/broadcom/bcm2835_thermal.c index 720760c..ba39647 100644 --- a/drivers/thermal/broadcom/bcm2835_thermal.c +++ b/drivers/thermal/broadcom/bcm2835_thermal.c @@ -119,8 +119,7 @@ static const struct debugfs_reg32 bcm2835_thermal_regs[] = { static void bcm2835_thermal_debugfs(struct platform_device *pdev) { - struct thermal_zone_device *tz = platform_get_drvdata(pdev); - struct bcm2835_thermal_data *data = tz->devdata; + struct bcm2835_thermal_data *data = platform_get_drvdata(pdev); struct debugfs_regset32 *regset; data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL); @@ -266,7 +265,7 @@ static int bcm2835_thermal_probe(struct platform_device *pdev) data->tz = tz; - platform_set_drvdata(pdev, tz); + platform_set_drvdata(pdev, data); /* * Thermal_zone doesn't enable hwmon as default, @@ -290,8 +289,8 @@ static int bcm2835_thermal_probe(struct platform_device *pdev) static int bcm2835_thermal_remove(struct platform_device *pdev) { - struct thermal_zone_device *tz = platform_get_drvdata(pdev); - struct bcm2835_thermal_data *data = tz->devdata; + struct bcm2835_thermal_data *data = platform_get_drvdata(pdev); + struct thermal_zone_device *tz = data->tz; debugfs_remove_recursive(data->debugfsdir); thermal_zone_of_sensor_unregister(&pdev->dev, tz);
"cat /sys/kernel/debug/bcm2835_thermal/regset" causes a NULL pointer dereference in bcm2835_thermal_debugfs. The driver makes use of the implementation details of the thermal framework to retrieve a pointer to its private data from a struct thermal_zone_device, and gets it wrong - leading to the crash. Instead, store its private data as the drvdata and retrieve the thermal_zone_device pointer from it. Fixes: bcb7dd9ef206 ("thermal: bcm2835: add thermal driver for bcm2835 SoC") Signed-off-by: Phil Elwell <phil@raspberrypi.org> --- drivers/thermal/broadcom/bcm2835_thermal.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)