[PATCH] ASoC: Intel: SST: fix platform device leak on probe failure

[Guangshuo Li <lgs201920130244@gmail.com>]

sst_acpi_probe() registers platform devices for the SST platform and
machine drivers using platform_device_register_data(), but does not
unregister them when later probe steps fail.

If machine device registration fails, the already registered SST platform
device is left registered. The same leak happens when
sst_platform_get_resources() or sst_context_init() fails after both
platform devices have been successfully registered.

A registered platform device owns resources allocated by the platform
device core and must be released with platform_device_unregister() so
that the device reference is dropped and platform_device_release() can
free the backing platform_object.

Unregister the created platform devices on all failure paths to restore
the missing cleanup.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fixes: caf94ed8629a ("ASoC: Intel: bytcr_rt5640: fixup DAI codec_name with HID")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 sound/soc/intel/atom/sst/sst_acpi.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
index 73624e1b138a..a1f16083bd3d 100644
--- a/sound/soc/intel/atom/sst/sst_acpi.c
+++ b/sound/soc/intel/atom/sst/sst_acpi.c
@@ -352,7 +352,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
 	if (IS_ERR(mdev)) {
 		dev_err(dev, "Failed to create machine device: %s\n",
 			mach->drv_name);
-		return PTR_ERR(mdev);
+		ret = PTR_ERR(mdev);
+		goto err_unregister_plat_dev;
 	}
 
 	/* Fill sst platform data */
@@ -361,15 +362,21 @@ static int sst_acpi_probe(struct platform_device *pdev)
 
 	ret = sst_platform_get_resources(ctx);
 	if (ret)
-		return ret;
+		goto err_unregister_mdev;
 
 	ret = sst_context_init(ctx);
 	if (ret < 0)
-		return ret;
+		goto err_unregister_mdev;
 
 	sst_configure_runtime_pm(ctx);
 	platform_set_drvdata(pdev, ctx);
 	return ret;
+
+err_unregister_mdev:
+	platform_device_unregister(mdev);
+err_unregister_plat_dev:
+	platform_device_unregister(plat_dev);
+	return ret;
 }
 
 /**
-- 
2.43.0