[PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[Haoxiang Li]

enable_sensor_store() can call set_power_report_state(), which
dereferences sensor_inst->power_state and sensor_inst->report_state.
These pointers refer to entries in sensor_inst->fields.

Create the field attributes before exposing the enable_sensor sysfs
attribute, so enable_sensor cannot be accessed before the state it
depends on has been initialized.

On remove, delete enable_sensor before freeing the field attributes,
so a concurrent sysfs write cannot dereference freed memory through
power_state or report_state.

Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
---
 drivers/hid/hid-sensor-custom.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-sensor-custom.c
index afffea894021..6b0da2e0e1c9 100644
--- a/drivers/hid/hid-sensor-custom.c
+++ b/drivers/hid/hid-sensor-custom.c
@@ -1005,26 +1005,26 @@ static int hid_sensor_custom_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
-				 &enable_sensor_attr_group);
+	ret = hid_sensor_custom_add_attributes(sensor_inst);
 	if (ret)
 		goto err_remove_callback;
 
-	ret = hid_sensor_custom_add_attributes(sensor_inst);
+	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
+				 &enable_sensor_attr_group);
 	if (ret)
-		goto err_remove_group;
+		goto err_remove_attributes;
 
 	ret = hid_sensor_custom_dev_if_add(sensor_inst);
 	if (ret)
-		goto err_remove_attributes;
+		goto err_remove_group;
 
 	return 0;
 
-err_remove_attributes:
-	hid_sensor_custom_remove_attributes(sensor_inst);
 err_remove_group:
 	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
 			   &enable_sensor_attr_group);
+err_remove_attributes:
+	hid_sensor_custom_remove_attributes(sensor_inst);
 err_remove_callback:
 	sensor_hub_remove_callback(hsdev, hsdev->usage);
 
@@ -1042,9 +1042,10 @@ static void hid_sensor_custom_remove(struct platform_device *pdev)
 	}
 
 	hid_sensor_custom_dev_if_remove(sensor_inst);
-	hid_sensor_custom_remove_attributes(sensor_inst);
+	/* Remove enable_sensor first as it uses fields via power_state/report_state. */
 	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
 			   &enable_sensor_attr_group);
+	hid_sensor_custom_remove_attributes(sensor_inst);
 	sensor_hub_remove_callback(hsdev, hsdev->usage);
 }
 
-- 
2.25.1

[PATCH v3 2/2] HID: sensor: custom: Fix field sysfs group cleanup on failure

[Haoxiang Li]

hid_sensor_custom_add_attributes() creates one sysfs group for each
custom sensor field. If sysfs_create_group() fails after some groups
have already been created, the function returns the error without
removing the previously created groups.

Add a local unwind path to remove the groups that were already created.
With enable_sensor exposed only after the field attributes are ready,
this path can free sensor_inst->fields without leaving enable_sensor
able to access pointers into that array.

Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor support")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
---
 drivers/hid/hid-sensor-custom.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-sensor-custom.c
index 6b0da2e0e1c9..c2b425afd951 100644
--- a/drivers/hid/hid-sensor-custom.c
+++ b/drivers/hid/hid-sensor-custom.c
@@ -609,7 +609,7 @@ static int hid_sensor_custom_add_attributes(struct hid_sensor_custom
 					 &sensor_inst->fields[i].
 					 hid_custom_attribute_group);
 		if (ret)
-			break;
+			goto err_remove_groups;
 
 		/* For power or report field store indexes */
 		if (sensor_inst->fields[i].attribute.attrib_id ==
@@ -621,6 +621,13 @@ static int hid_sensor_custom_add_attributes(struct hid_sensor_custom
 	}
 
 	return ret;
+
+err_remove_groups:
+	while (--i >= 0)
+		sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
+				   &sensor_inst->fields[i].hid_custom_attribute_group);
+	kfree(sensor_inst->fields);
+	return ret;
 }
 
 static void hid_sensor_custom_remove_attributes(struct hid_sensor_custom *
-- 
2.25.1

Re: [PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[srinivas pandruvada]

On Tue, 2026-07-07 at 15:15 +0800, Haoxiang Li wrote:
> enable_sensor_store() can call set_power_report_state(), which
> dereferences sensor_inst->power_state and sensor_inst->report_state.
> These pointers refer to entries in sensor_inst->fields.
> 
> Create the field attributes before exposing the enable_sensor sysfs
> attribute, so enable_sensor cannot be accessed before the state it
> depends on has been initialized.
> 
> On remove, delete enable_sensor before freeing the field attributes,
> so a concurrent sysfs write cannot dereference freed memory through
> power_state or report_state.
> 
> Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
> Link:
> https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
> Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor
> support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/hid/hid-sensor-custom.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-
> sensor-custom.c
> index afffea894021..6b0da2e0e1c9 100644
> --- a/drivers/hid/hid-sensor-custom.c
> +++ b/drivers/hid/hid-sensor-custom.c
> @@ -1005,26 +1005,26 @@ static int hid_sensor_custom_probe(struct
> platform_device *pdev)
>  		return ret;
>  	}
>  
> -	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
> -				 &enable_sensor_attr_group);
> +	ret = hid_sensor_custom_add_attributes(sensor_inst);
>  	if (ret)
>  		goto err_remove_callback;
>  
> -	ret = hid_sensor_custom_add_attributes(sensor_inst);
> +	ret = sysfs_create_group(&sensor_inst->pdev->dev.kobj,
> +				 &enable_sensor_attr_group);
>  	if (ret)
> -		goto err_remove_group;
> +		goto err_remove_attributes;
>  
>  	ret = hid_sensor_custom_dev_if_add(sensor_inst);
>  	if (ret)
> -		goto err_remove_attributes;
> +		goto err_remove_group;
>  
>  	return 0;
>  
> -err_remove_attributes:
> -	hid_sensor_custom_remove_attributes(sensor_inst);
>  err_remove_group:
>  	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
>  			   &enable_sensor_attr_group);
> +err_remove_attributes:
> +	hid_sensor_custom_remove_attributes(sensor_inst);
>  err_remove_callback:
>  	sensor_hub_remove_callback(hsdev, hsdev->usage);
>  
> @@ -1042,9 +1042,10 @@ static void hid_sensor_custom_remove(struct
> platform_device *pdev)
>  	}
>  
>  	hid_sensor_custom_dev_if_remove(sensor_inst);
> -	hid_sensor_custom_remove_attributes(sensor_inst);
> +	/* Remove enable_sensor first as it uses fields via
> power_state/report_state. */
>  	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
>  			   &enable_sensor_attr_group);
> +	hid_sensor_custom_remove_attributes(sensor_inst);
>  	sensor_hub_remove_callback(hsdev, hsdev->usage);
>  }
>  

Re: [PATCH v3 2/2] HID: sensor: custom: Fix field sysfs group cleanup on failure

[srinivas pandruvada]

On Tue, 2026-07-07 at 15:15 +0800, Haoxiang Li wrote:
> hid_sensor_custom_add_attributes() creates one sysfs group for each
> custom sensor field. If sysfs_create_group() fails after some groups
> have already been created, the function returns the error without
> removing the previously created groups.
> 
> Add a local unwind path to remove the groups that were already
> created.
> With enable_sensor exposed only after the field attributes are ready,
> this path can free sensor_inst->fields without leaving enable_sensor
> able to access pointers into that array.
> 
> Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor
> support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>

Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

> ---
>  drivers/hid/hid-sensor-custom.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-
> sensor-custom.c
> index 6b0da2e0e1c9..c2b425afd951 100644
> --- a/drivers/hid/hid-sensor-custom.c
> +++ b/drivers/hid/hid-sensor-custom.c
> @@ -609,7 +609,7 @@ static int
> hid_sensor_custom_add_attributes(struct hid_sensor_custom
>  					 &sensor_inst->fields[i].
>  					
> hid_custom_attribute_group);
>  		if (ret)
> -			break;
> +			goto err_remove_groups;
>  
>  		/* For power or report field store indexes */
>  		if (sensor_inst->fields[i].attribute.attrib_id ==
> @@ -621,6 +621,13 @@ static int
> hid_sensor_custom_add_attributes(struct hid_sensor_custom
>  	}
>  
>  	return ret;
> +
> +err_remove_groups:
> +	while (--i >= 0)
> +		sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
> +				   &sensor_inst-
> >fields[i].hid_custom_attribute_group);
> +	kfree(sensor_inst->fields);
> +	return ret;
>  }
>  
>  static void hid_sensor_custom_remove_attributes(struct
> hid_sensor_custom *

Re: [PATCH v3 1/2] HID: sensor: custom: Fix use-after-free in enable_sensor

[Jiri Kosina]

On Tue, 7 Jul 2026, Haoxiang Li wrote:

> enable_sensor_store() can call set_power_report_state(), which
> dereferences sensor_inst->power_state and sensor_inst->report_state.
> These pointers refer to entries in sensor_inst->fields.
> 
> Create the field attributes before exposing the enable_sensor sysfs
> attribute, so enable_sensor cannot be accessed before the state it
> depends on has been initialized.
> 
> On remove, delete enable_sensor before freeing the field attributes,
> so a concurrent sysfs write cannot dereference freed memory through
> power_state or report_state.
> 
> Reported-by: Sashiko AI Review <sashiko-bot@kernel.org>
> Link: https://sashiko.dev/#/patchset/20260623021950.1736413-1-haoxiang_li2024@163.com?part=1
> Fixes: 4a7de0519df5 ("HID: sensor: Custom and Generic sensor support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs