[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@xxxxxxxxx>
---
 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