2018-08-13 17:19:44

by Dmitry Osipenko

Subject: [PATCH v1] thermal: core: Fix use-after-free in thermal_cooling_device_destroy_sysfs

This patch fixes use-after-free that was detected by KASAN. The bug is
triggered on a CPUFreq driver module unload by freeing 'cdev' on device
unregister and then using the freed structure during of the cdev's sysfs
data destruction. The solution is to unregister the sysfs at first, then
destroy sysfs data and finally release the cooling device.

Cc: <[email protected]> # v4.17+
Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs")
Signed-off-by: Dmitry Osipenko <[email protected]>
---
drivers/thermal/thermal_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 6ab982309e6a..441778100887 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1102,8 +1102,9 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
mutex_unlock(&thermal_list_lock);

ida_simple_remove(&thermal_cdev_ida, cdev->id);
- device_unregister(&cdev->device);
+ device_del(&cdev->device);
thermal_cooling_device_destroy_sysfs(cdev);
+ put_device(&cdev->device);
}
EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);

--
2.18.0

2018-09-03 06:25:21

by Viresh Kumar

Subject: Re: [PATCH v1] thermal: core: Fix use-after-free in thermal_cooling_device_destroy_sysfs

On 13-08-18, 20:14, Dmitry Osipenko wrote:
> This patch fixes use-after-free that was detected by KASAN. The bug is
> triggered on a CPUFreq driver module unload by freeing 'cdev' on device
> unregister and then using the freed structure during of the cdev's sysfs
> data destruction. The solution is to unregister the sysfs at first, then
> destroy sysfs data and finally release the cooling device.
>
> Cc: <[email protected]> # v4.17+
> Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs")
> Signed-off-by: Dmitry Osipenko <[email protected]>
> ---
> drivers/thermal/thermal_core.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 6ab982309e6a..441778100887 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1102,8 +1102,9 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> mutex_unlock(&thermal_list_lock);
>
> ida_simple_remove(&thermal_cdev_ida, cdev->id);
> - device_unregister(&cdev->device);
> + device_del(&cdev->device);
> thermal_cooling_device_destroy_sysfs(cdev);
> + put_device(&cdev->device);
> }
> EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);

Acked-by: Viresh Kumar <[email protected]>

--
viresh

2018-09-05 16:55:57

by Eduardo Valentin

Subject: Re: [PATCH v1] thermal: core: Fix use-after-free in thermal_cooling_device_destroy_sysfs

On Mon, Aug 13, 2018 at 08:14:00PM +0300, Dmitry Osipenko wrote:
> This patch fixes use-after-free that was detected by KASAN. The bug is
> triggered on a CPUFreq driver module unload by freeing 'cdev' on device
> unregister and then using the freed structure during of the cdev's sysfs
> data destruction. The solution is to unregister the sysfs at first, then
> destroy sysfs data and finally release the cooling device.
>
> Cc: <[email protected]> # v4.17+
> Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs")
> Signed-off-by: Dmitry Osipenko <[email protected]>

Acked-by: Eduardo Valentin <[email protected]>

Rui, can you please queue this one?

> ---
> drivers/thermal/thermal_core.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 6ab982309e6a..441778100887 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -1102,8 +1102,9 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
> mutex_unlock(&thermal_list_lock);
>
> ida_simple_remove(&thermal_cdev_ida, cdev->id);
> - device_unregister(&cdev->device);
> + device_del(&cdev->device);
> thermal_cooling_device_destroy_sysfs(cdev);
> + put_device(&cdev->device);
> }
> EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
>
> --
> 2.18.0
>