2021-10-15 15:15:53

by Yuanzheng Song

Subject: [PATCH -next] Fix null pointer dereference in thermal_release()

If both dev_set_name() and device_register() failed, then
null pointer dereference occurs in thermal_release() which
will use strncmp() to compare the name.

So fix it by adding dev_set_name() return value check.

Signed-off-by: Yuanzheng Song <[email protected]>
---
drivers/thermal/thermal_core.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 9e243d9f929e..6904b97fd6ea 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -904,6 +904,10 @@ __thermal_cooling_device_register(struct device_node *np,
goto out_kfree_cdev;
cdev->id = ret;

+ ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
+ if (ret)
+ goto out_ida_remove;
+
cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
if (!cdev->type) {
ret = -ENOMEM;
@@ -918,7 +922,6 @@ __thermal_cooling_device_register(struct device_node *np,
cdev->device.class = &thermal_class;
cdev->devdata = devdata;
thermal_cooling_device_setup_sysfs(cdev);
- dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
ret = device_register(&cdev->device);
if (ret)
goto out_kfree_type;
@@ -1229,6 +1232,10 @@ thermal_zone_device_register(const char *type, int trips, int mask,
tz->id = id;
strlcpy(tz->type, type, sizeof(tz->type));

+ result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
+ if (result)
+ goto remove_id;
+
if (!ops->critical)
ops->critical = thermal_zone_device_critical;

@@ -1250,7 +1257,6 @@ thermal_zone_device_register(const char *type, int trips, int mask,
/* A new thermal zone needs to be updated anyway. */
atomic_set(&tz->need_update, 1);

- dev_set_name(&tz->device, "thermal_zone%d", tz->id);
result = device_register(&tz->device);
if (result)
goto release_device;
--
2.25.1

2021-10-15 21:46:14

by Daniel Lezcano

Subject: Re: [PATCH -next] Fix null pointer dereference in thermal_release()

On 15/10/2021 10:32, Yuanzheng Song wrote:
> If both dev_set_name() and device_register() failed, then
> null pointer dereference occurs in thermal_release() which
> will use strncmp() to compare the name.
>
> So fix it by adding dev_set_name() return value check.
>
> Signed-off-by: Yuanzheng Song <[email protected]>

Applied, thanks

> ---
> drivers/thermal/thermal_core.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 9e243d9f929e..6904b97fd6ea 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -904,6 +904,10 @@ __thermal_cooling_device_register(struct device_node *np,
> goto out_kfree_cdev;
> cdev->id = ret;
>
> + ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
> + if (ret)
> + goto out_ida_remove;
> +
> cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
> if (!cdev->type) {
> ret = -ENOMEM;
> @@ -918,7 +922,6 @@ __thermal_cooling_device_register(struct device_node *np,
> cdev->device.class = &thermal_class;
> cdev->devdata = devdata;
> thermal_cooling_device_setup_sysfs(cdev);
> - dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
> ret = device_register(&cdev->device);
> if (ret)
> goto out_kfree_type;
> @@ -1229,6 +1232,10 @@ thermal_zone_device_register(const char *type, int trips, int mask,
> tz->id = id;
> strlcpy(tz->type, type, sizeof(tz->type));
>
> + result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
> + if (result)
> + goto remove_id;
> +
> if (!ops->critical)
> ops->critical = thermal_zone_device_critical;
>
> @@ -1250,7 +1257,6 @@ thermal_zone_device_register(const char *type, int trips, int mask,
> /* A new thermal zone needs to be updated anyway. */
> atomic_set(&tz->need_update, 1);
>
> - dev_set_name(&tz->device, "thermal_zone%d", tz->id);
> result = device_register(&tz->device);
> if (result)
> goto release_device;
>


--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog