[PATCH] usb: misc: ljca: Fix double free in error handling path

[PATCH] usb: misc: ljca: Fix double free in error handling path

[Yongzhi Liu]

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), callback function ljca_auxdev_release
calls kfree(auxdev->dev.platform_data) to free the parameter data
of the function ljca_new_client_device. The callers of
ljca_new_client_device shouldn't call kfree() again
in the error handling path to free the platform data.

Fix this by cleaning up the redundant kfree().

Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
---
 drivers/usb/misc/usb-ljca.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
index 35770e608c64..be702364be08 100644
--- a/drivers/usb/misc/usb-ljca.c
+++ b/drivers/usb/misc/usb-ljca.c
@@ -590,12 +590,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
 		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
 	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
 
-	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
+	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
 				     gpio_info, LJCA_GPIO_ACPI_ADR);
-	if (ret)
-		kfree(gpio_info);
-
-	return ret;
 }
 
 static int ljca_enumerate_i2c(struct ljca_adapter *adap)
@@ -626,13 +622,9 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
 		i2c_info->capacity = desc->info[i].capacity;
 		i2c_info->intr_pin = desc->info[i].intr_pin;
 
-		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
+		return ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
 					     "ljca-i2c", i2c_info,
 					     LJCA_I2C1_ACPI_ADR + i);
-		if (ret) {
-			kfree(i2c_info);
-			return ret;
-		}
 	}
 
 	return 0;
@@ -666,13 +658,9 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
 		spi_info->id = desc->info[i].id;
 		spi_info->capacity = desc->info[i].capacity;
 
-		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
+		return ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
 					     "ljca-spi", spi_info,
 					     LJCA_SPI1_ACPI_ADR + i);
-		if (ret) {
-			kfree(spi_info);
-			return ret;
-		}
 	}
 
 	return 0;
-- 
2.36.1

Re: [PATCH] usb: misc: ljca: Fix double free in error handling path

[Hans de Goede]

Hi,

On 3/6/24 14:00, Yongzhi Liu wrote:
> When auxiliary_device_add() returns error and then calls
> auxiliary_device_uninit(), callback function ljca_auxdev_release
> calls kfree(auxdev->dev.platform_data) to free the parameter data
> of the function ljca_new_client_device. The callers of
> ljca_new_client_device shouldn't call kfree() again
> in the error handling path to free the platform data.
> 
> Fix this by cleaning up the redundant kfree().

If things fail in ljca_new_client_device() before 
auxiliary_device_init() gets called (or if that call fails)
then auxiliary_device_uninit() will NOT be called leading to
a memory-leak.

So this patch is no good as is.

To properly fix this you must make ljca_new_client_device() 
always take ownership of the passed in platform_data and
make it also kfree() the passed in platform_data on errors
which happen before auxiliary_device_init() succeeds.

Regards,

Hans





> 
> Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
> Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
> ---
>  drivers/usb/misc/usb-ljca.c | 18 +++---------------
>  1 file changed, 3 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
> index 35770e608c64..be702364be08 100644
> --- a/drivers/usb/misc/usb-ljca.c
> +++ b/drivers/usb/misc/usb-ljca.c
> @@ -590,12 +590,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
>  		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
>  	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
>  
> -	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
> +	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
>  				     gpio_info, LJCA_GPIO_ACPI_ADR);
> -	if (ret)
> -		kfree(gpio_info);
> -
> -	return ret;
>  }
>  
>  static int ljca_enumerate_i2c(struct ljca_adapter *adap)
> @@ -626,13 +622,9 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
>  		i2c_info->capacity = desc->info[i].capacity;
>  		i2c_info->intr_pin = desc->info[i].intr_pin;
>  
> -		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
> +		return ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
>  					     "ljca-i2c", i2c_info,
>  					     LJCA_I2C1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(i2c_info);
> -			return ret;
> -		}
>  	}
>  
>  	return 0;
> @@ -666,13 +658,9 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
>  		spi_info->id = desc->info[i].id;
>  		spi_info->capacity = desc->info[i].capacity;
>  
> -		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
> +		return ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
>  					     "ljca-spi", spi_info,
>  					     LJCA_SPI1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(spi_info);
> -			return ret;
> -		}
>  	}
>  
>  	return 0;

[PATCH V2] usb: misc: ljca: Fix double free in error handling path

[Yongzhi Liu]

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), callback function ljca_auxdev_release
calls kfree(auxdev->dev.platform_data) to free the parameter data
of the function ljca_new_client_device. The callers of
ljca_new_client_device shouldn't call kfree() again
in the error handling path to free the platform data.

Fix this by cleaning up the redundant kfree() in all callers and
adding kfree() the passed in platform_data on errors which happen
before auxiliary_device_init() succeeds .

Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
---
 drivers/usb/misc/usb-ljca.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
index 35770e608c64..bd9ccbea6e72 100644
--- a/drivers/usb/misc/usb-ljca.c
+++ b/drivers/usb/misc/usb-ljca.c
@@ -518,8 +518,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
 	int ret;
 
 	client = kzalloc(sizeof *client, GFP_KERNEL);
-	if (!client)
+	if (!client) {
+		kfree(data);
 		return -ENOMEM;
+	}
 
 	client->type = type;
 	client->id = id;
@@ -535,8 +537,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
 	auxdev->dev.release = ljca_auxdev_release;
 
 	ret = auxiliary_device_init(auxdev);
-	if (ret)
+	if (ret) {
+		kfree(data);
 		goto err_free;
+	}
 
 	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
 
@@ -590,12 +594,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
 		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
 	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
 
-	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
+	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
 				     gpio_info, LJCA_GPIO_ACPI_ADR);
-	if (ret)
-		kfree(gpio_info);
-
-	return ret;
 }
 
 static int ljca_enumerate_i2c(struct ljca_adapter *adap)
@@ -626,13 +626,9 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
 		i2c_info->capacity = desc->info[i].capacity;
 		i2c_info->intr_pin = desc->info[i].intr_pin;
 
-		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
+		return ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
 					     "ljca-i2c", i2c_info,
 					     LJCA_I2C1_ACPI_ADR + i);
-		if (ret) {
-			kfree(i2c_info);
-			return ret;
-		}
 	}
 
 	return 0;
@@ -666,13 +662,9 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
 		spi_info->id = desc->info[i].id;
 		spi_info->capacity = desc->info[i].capacity;
 
-		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
+		return ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
 					     "ljca-spi", spi_info,
 					     LJCA_SPI1_ACPI_ADR + i);
-		if (ret) {
-			kfree(spi_info);
-			return ret;
-		}
 	}
 
 	return 0;
-- 
2.36.1

Re: [PATCH V2] usb: misc: ljca: Fix double free in error handling path

[Hans de Goede]

Hi Yongzhi Liu,

On 3/7/24 12:57, Yongzhi Liu wrote:
> When auxiliary_device_add() returns error and then calls
> auxiliary_device_uninit(), callback function ljca_auxdev_release
> calls kfree(auxdev->dev.platform_data) to free the parameter data
> of the function ljca_new_client_device. The callers of
> ljca_new_client_device shouldn't call kfree() again
> in the error handling path to free the platform data.
> 
> Fix this by cleaning up the redundant kfree() in all callers and
> adding kfree() the passed in platform_data on errors which happen
> before auxiliary_device_init() succeeds .
> 
> Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
> Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
> ---
>  drivers/usb/misc/usb-ljca.c | 26 +++++++++-----------------
>  1 file changed, 9 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
> index 35770e608c64..bd9ccbea6e72 100644
> --- a/drivers/usb/misc/usb-ljca.c
> +++ b/drivers/usb/misc/usb-ljca.c
> @@ -518,8 +518,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
>  	int ret;
>  
>  	client = kzalloc(sizeof *client, GFP_KERNEL);
> -	if (!client)
> +	if (!client) {
> +		kfree(data);
>  		return -ENOMEM;
> +	}
>  
>  	client->type = type;
>  	client->id = id;
> @@ -535,8 +537,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
>  	auxdev->dev.release = ljca_auxdev_release;
>  
>  	ret = auxiliary_device_init(auxdev);
> -	if (ret)
> +	if (ret) {
> +		kfree(data);
>  		goto err_free;
> +	}
>  
>  	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
>  
> @@ -590,12 +594,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
>  		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
>  	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
>  
> -	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
> +	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
>  				     gpio_info, LJCA_GPIO_ACPI_ADR);
> -	if (ret)
> -		kfree(gpio_info);
> -
> -	return ret;
>  }
>  
>  static int ljca_enumerate_i2c(struct ljca_adapter *adap)
> @@ -626,13 +626,9 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
>  		i2c_info->capacity = desc->info[i].capacity;
>  		i2c_info->intr_pin = desc->info[i].intr_pin;
>  
> -		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
> +		return ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
>  					     "ljca-i2c", i2c_info,
>  					     LJCA_I2C1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(i2c_info);
> -			return ret;
> -		}

This is in a for loop, by using:

		return ljca_new_client_device(...);

you are now only creating the first ljca-i2c controller, while
there may be more instead just drop the kfree() from the if (ret) {}
block:

		ret = ljca_new_client_device(...);
		if (ret)
			return ret;

Sorry for not noticing this with the v1 posting.

>  	}
>  
>  	return 0;
> @@ -666,13 +662,9 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
>  		spi_info->id = desc->info[i].id;
>  		spi_info->capacity = desc->info[i].capacity;
>  
> -		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
> +		return ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
>  					     "ljca-spi", spi_info,
>  					     LJCA_SPI1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(spi_info);
> -			return ret;
> -		}
>  	}

Same remark as with the creation of the i2c controllers, please use:

		ret = ljca_new_client_device(...);
		if (ret)
			return ret;

Regards,

Hans

[PATCH V3] usb: misc: ljca: Fix double free in error handling path

[Yongzhi Liu]

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), callback function ljca_auxdev_release
calls kfree(auxdev->dev.platform_data) to free the parameter data
of the function ljca_new_client_device. The callers of
ljca_new_client_device shouldn't call kfree() again
in the error handling path to free the platform data.

Fix this by cleaning up the redundant kfree() in all callers and
adding kfree() the passed in platform_data on errors which happen
before auxiliary_device_init() succeeds .

Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>
---
 drivers/usb/misc/usb-ljca.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
index 35770e608c64..2d30fc1be306 100644
--- a/drivers/usb/misc/usb-ljca.c
+++ b/drivers/usb/misc/usb-ljca.c
@@ -518,8 +518,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
 	int ret;
 
 	client = kzalloc(sizeof *client, GFP_KERNEL);
-	if (!client)
+	if (!client) {
+		kfree(data);
 		return -ENOMEM;
+	}
 
 	client->type = type;
 	client->id = id;
@@ -535,8 +537,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
 	auxdev->dev.release = ljca_auxdev_release;
 
 	ret = auxiliary_device_init(auxdev);
-	if (ret)
+	if (ret) {
+		kfree(data);
 		goto err_free;
+	}
 
 	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
 
@@ -590,12 +594,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
 		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
 	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
 
-	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
+	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
 				     gpio_info, LJCA_GPIO_ACPI_ADR);
-	if (ret)
-		kfree(gpio_info);
-
-	return ret;
 }
 
 static int ljca_enumerate_i2c(struct ljca_adapter *adap)
@@ -629,10 +629,8 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
 		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
 					     "ljca-i2c", i2c_info,
 					     LJCA_I2C1_ACPI_ADR + i);
-		if (ret) {
-			kfree(i2c_info);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
@@ -669,10 +667,8 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
 		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
 					     "ljca-spi", spi_info,
 					     LJCA_SPI1_ACPI_ADR + i);
-		if (ret) {
-			kfree(spi_info);
+		if (ret)
 			return ret;
-		}
 	}
 
 	return 0;
-- 
2.36.1

Re: [PATCH V3] usb: misc: ljca: Fix double free in error handling path

[Hans de Goede]

Hi,

On 3/11/24 1:57 PM, Yongzhi Liu wrote:
> When auxiliary_device_add() returns error and then calls
> auxiliary_device_uninit(), callback function ljca_auxdev_release
> calls kfree(auxdev->dev.platform_data) to free the parameter data
> of the function ljca_new_client_device. The callers of
> ljca_new_client_device shouldn't call kfree() again
> in the error handling path to free the platform data.
> 
> Fix this by cleaning up the redundant kfree() in all callers and
> adding kfree() the passed in platform_data on errors which happen
> before auxiliary_device_init() succeeds .
> 
> Fixes: acd6199f195d ("usb: Add support for Intel LJCA device")
> Signed-off-by: Yongzhi Liu <hyperlyzcs@gmail.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans



> ---
>  drivers/usb/misc/usb-ljca.c | 22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/misc/usb-ljca.c b/drivers/usb/misc/usb-ljca.c
> index 35770e608c64..2d30fc1be306 100644
> --- a/drivers/usb/misc/usb-ljca.c
> +++ b/drivers/usb/misc/usb-ljca.c
> @@ -518,8 +518,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
>  	int ret;
>  
>  	client = kzalloc(sizeof *client, GFP_KERNEL);
> -	if (!client)
> +	if (!client) {
> +		kfree(data);
>  		return -ENOMEM;
> +	}
>  
>  	client->type = type;
>  	client->id = id;
> @@ -535,8 +537,10 @@ static int ljca_new_client_device(struct ljca_adapter *adap, u8 type, u8 id,
>  	auxdev->dev.release = ljca_auxdev_release;
>  
>  	ret = auxiliary_device_init(auxdev);
> -	if (ret)
> +	if (ret) {
> +		kfree(data);
>  		goto err_free;
> +	}
>  
>  	ljca_auxdev_acpi_bind(adap, auxdev, adr, id);
>  
> @@ -590,12 +594,8 @@ static int ljca_enumerate_gpio(struct ljca_adapter *adap)
>  		valid_pin[i] = get_unaligned_le32(&desc->bank_desc[i].valid_pins);
>  	bitmap_from_arr32(gpio_info->valid_pin_map, valid_pin, gpio_num);
>  
> -	ret = ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
> +	return ljca_new_client_device(adap, LJCA_CLIENT_GPIO, 0, "ljca-gpio",
>  				     gpio_info, LJCA_GPIO_ACPI_ADR);
> -	if (ret)
> -		kfree(gpio_info);
> -
> -	return ret;
>  }
>  
>  static int ljca_enumerate_i2c(struct ljca_adapter *adap)
> @@ -629,10 +629,8 @@ static int ljca_enumerate_i2c(struct ljca_adapter *adap)
>  		ret = ljca_new_client_device(adap, LJCA_CLIENT_I2C, i,
>  					     "ljca-i2c", i2c_info,
>  					     LJCA_I2C1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(i2c_info);
> +		if (ret)
>  			return ret;
> -		}
>  	}
>  
>  	return 0;
> @@ -669,10 +667,8 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap)
>  		ret = ljca_new_client_device(adap, LJCA_CLIENT_SPI, i,
>  					     "ljca-spi", spi_info,
>  					     LJCA_SPI1_ACPI_ADR + i);
> -		if (ret) {
> -			kfree(spi_info);
> +		if (ret)
>  			return ret;
> -		}
>  	}
>  
>  	return 0;