[PATCH v4 1/2] platform/x86: int1092: Fix potential memory leak in sar_probe()

The memory allocated for device_mode_info in parse_package() called by
sar_get_data() is not freed in some of the error paths in sar_probe().
Fix that by converting to use device managed allocations.

Fixes: dcfbd31ef4bc ("platform/x86: BIOS SAR driver for Intel M.2 Modem")
Cc: [email protected]
Signed-off-by: Abdun Nihaal <[email protected]>
---
Compile tested only. Issue found using static analysis.

v1->v2:
- Changed the patch to instead use device managed allocations for both
  the device_mode_info and the context structure, as suggested by Ilpo
  Järvinen.
v2->v3:
- Align the arguments to the opening paranthesis as suggested by Ilpo
  Järvinen.
v3->v4:
- No change

Link to v1: https://patchwork.kernel.org/project/platform-driver-x86/patch/[email protected]/
Link to v2: https://patchwork.kernel.org/project/platform-driver-x86/patch/[email protected]/
---
 drivers/platform/x86/intel/int1092/intel_sar.c | 32 ++++++++------------------
 1 file changed, 10 insertions(+), 22 deletions(-)

diff --git a/drivers/platform/x86/intel/int1092/intel_sar.c b/drivers/platform/x86/intel/int1092/intel_sar.c
index 849f7b415c1e..7263114f0b3d 100644
--- a/drivers/platform/x86/intel/int1092/intel_sar.c
+++ b/drivers/platform/x86/intel/int1092/intel_sar.c
@@ -91,8 +91,10 @@ static acpi_status parse_package(struct wwan_sar_context *context, union acpi_ob
 	    item->package.count <= data->total_dev_mode)
 		return AE_ERROR;
 
-	data->device_mode_info = kmalloc_objs(struct wwan_device_mode_info,
-					      data->total_dev_mode);
+	data->device_mode_info = devm_kmalloc_array(&context->sar_device->dev,
+						    data->total_dev_mode,
+						    sizeof(*data->device_mode_info),
+						    GFP_KERNEL);
 	if (!data->device_mode_info)
 		return AE_ERROR;
 
@@ -253,7 +255,7 @@ static int sar_probe(struct platform_device *device)
 	if (!handle)
 		return -ENODEV;
 
-	context = kzalloc_obj(*context);
+	context = devm_kzalloc(&device->dev, sizeof(*context), GFP_KERNEL);
 	if (!context)
 		return -ENOMEM;
 
@@ -264,7 +266,7 @@ static int sar_probe(struct platform_device *device)
 	result = guid_parse(SAR_DSM_UUID, &context->guid);
 	if (result) {
 		dev_err(&device->dev, "SAR UUID parse error: %d\n", result);
-		goto r_free;
+		return result;
 	}
 
 	for (reg = 0; reg < MAX_REGULATORY; reg++)
@@ -272,43 +274,29 @@ static int sar_probe(struct platform_device *device)
 
 	if (sar_get_device_mode(device) != AE_OK) {
 		dev_err(&device->dev, "Failed to get device mode\n");
-		result = -EIO;
-		goto r_free;
+		return -EIO;
 	}
 
 	result = sysfs_create_group(&device->dev.kobj, &intcsar_group);
 	if (result) {
 		dev_err(&device->dev, "sysfs creation failed\n");
-		goto r_free;
+		return result;
 	}
 
 	if (acpi_install_notify_handler(ACPI_HANDLE(&device->dev), ACPI_DEVICE_NOTIFY,
 					sar_notify, (void *)device) != AE_OK) {
 		dev_err(&device->dev, "Failed acpi_install_notify_handler\n");
-		result = -EIO;
-		goto r_sys;
+		sysfs_remove_group(&device->dev.kobj, &intcsar_group);
+		return -EIO;
 	}
 	return 0;
-
-r_sys:
-	sysfs_remove_group(&device->dev.kobj, &intcsar_group);
-r_free:
-	kfree(context);
-	return result;
 }
 
 static void sar_remove(struct platform_device *device)
 {
-	struct wwan_sar_context *context = dev_get_drvdata(&device->dev);
-	int reg;
-
 	acpi_remove_notify_handler(ACPI_HANDLE(&device->dev),
 				   ACPI_DEVICE_NOTIFY, sar_notify);
 	sysfs_remove_group(&device->dev.kobj, &intcsar_group);
-	for (reg = 0; reg < MAX_REGULATORY; reg++)
-		kfree(context->config_data[reg].device_mode_info);
-
-	kfree(context);
 }
 
 static struct platform_driver sar_driver = {

-- 
2.43.0