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FAILED: patch "[PATCH] media: davinci: vpif: fix use-after-free on driver unbind" failed to apply to 5.10-stable tree

PATCH [email protected] 1 participant 1 message Apr 2, 2022

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Stable branch Media (V4L/DVB)
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The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 43acb728bbc40169d2e2425e84a80068270974be Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 22 Dec 2021 15:20:24 +0100
Subject: [PATCH] media: davinci: vpif: fix use-after-free on driver unbind

The driver allocates and registers two platform device structures during probe, but the devices were never deregistered on driver unbind.

This results in a use-after-free on driver unbind as the device structures were allocated using devres and would be freed by driver core when remove() returns.

Fix this by adding the missing deregistration calls to the remove() callback and failing probe on registration errors.

Note that the platform device structures must be freed using a proper release callback to avoid leaking associated resources like device names.

Fixes 479f7a118105 ("[media] davinci: vpif: adaptions for DT support")
Cc [email protected] # 4.12
Cc Kevin Hilman <[email protected]>
Signed-off-by Johan Hovold <[email protected]>
Reviewed-by Lad Prabhakar <[email protected]>
Signed-off-by Hans Verkuil <[email protected]>
Signed-off-by Mauro Carvalho Chehab <[email protected]>
drivers/media/platform/davinci/vpif.c +71 -26
index 1f5eacf48580..4a260f4ed236 100644
@@ -41,6 +41,11 @@ MODULE_ALIAS("platform:" VPIF_DRIVER_NAME);
 #define VPIF_CH2_MAX_MODES	15
 #define VPIF_CH3_MAX_MODES	2
 
+struct vpif_data {
+	struct platform_device *capture;
+	struct platform_device *display;
+};
+
 DEFINE_SPINLOCK(vpif_lock);
 EXPORT_SYMBOL_GPL(vpif_lock);
 

@@ -423,17 +428,31 @@ int vpif_channel_getfid(u8 channel_id)
 }
 EXPORT_SYMBOL(vpif_channel_getfid);
 
+static void vpif_pdev_release(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	kfree(pdev);
+}
+
 static int vpif_probe(struct platform_device *pdev)
 {
 	static struct resource *res_irq;
 	struct platform_device *pdev_capture, *pdev_display;
 	struct device_node *endpoint = NULL;
+	struct vpif_data *data;
 	int ret;
 
 	vpif_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(vpif_base))
 		return PTR_ERR(vpif_base);
 
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, data);
+
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get(&pdev->dev);
 

@@ -461,49 +480,75 @@ static int vpif_probe(struct platform_device *pdev)
 		goto err_put_rpm;
 	}
 
-	pdev_capture = devm_kzalloc(&pdev->dev, sizeof(*pdev_capture),
-				    GFP_KERNEL);
-	if (pdev_capture) {
-		pdev_capture->name = "vpif_capture";
-		pdev_capture->id = -1;
-		pdev_capture->resource = res_irq;
-		pdev_capture->num_resources = 1;
-		pdev_capture->dev.dma_mask = pdev->dev.dma_mask;
-		pdev_capture->dev.coherent_dma_mask = pdev->dev.coherent_dma_mask;
-		pdev_capture->dev.parent = &pdev->dev;
-		platform_device_register(pdev_capture);
-	} else {
-		dev_warn(&pdev->dev, "Unable to allocate memory for pdev_capture.\n");
+	pdev_capture = kzalloc(sizeof(*pdev_capture), GFP_KERNEL);
+	if (!pdev_capture) {
+		ret = -ENOMEM;
+		goto err_put_rpm;
 	}
 
-	pdev_display = devm_kzalloc(&pdev->dev, sizeof(*pdev_display),
-				    GFP_KERNEL);
-	if (pdev_display) {
-		pdev_display->name = "vpif_display";
-		pdev_display->id = -1;
-		pdev_display->resource = res_irq;
-		pdev_display->num_resources = 1;
-		pdev_display->dev.dma_mask = pdev->dev.dma_mask;
-		pdev_display->dev.coherent_dma_mask = pdev->dev.coherent_dma_mask;
-		pdev_display->dev.parent = &pdev->dev;
-		platform_device_register(pdev_display);
-	} else {
-		dev_warn(&pdev->dev, "Unable to allocate memory for pdev_display.\n");
+	pdev_capture->name = "vpif_capture";
+	pdev_capture->id = -1;
+	pdev_capture->resource = res_irq;
+	pdev_capture->num_resources = 1;
+	pdev_capture->dev.dma_mask = pdev->dev.dma_mask;
+	pdev_capture->dev.coherent_dma_mask = pdev->dev.coherent_dma_mask;
+	pdev_capture->dev.parent = &pdev->dev;
+	pdev_capture->dev.release = vpif_pdev_release;
+
+	ret = platform_device_register(pdev_capture);
+	if (ret)
+		goto err_put_pdev_capture;
+
+	pdev_display = kzalloc(sizeof(*pdev_display), GFP_KERNEL);
+	if (!pdev_display) {
+		ret = -ENOMEM;
+		goto err_put_pdev_capture;
 	}
 
+	pdev_display->name = "vpif_display";
+	pdev_display->id = -1;
+	pdev_display->resource = res_irq;
+	pdev_display->num_resources = 1;
+	pdev_display->dev.dma_mask = pdev->dev.dma_mask;
+	pdev_display->dev.coherent_dma_mask = pdev->dev.coherent_dma_mask;
+	pdev_display->dev.parent = &pdev->dev;
+	pdev_display->dev.release = vpif_pdev_release;
+
+	ret = platform_device_register(pdev_display);
+	if (ret)
+		goto err_put_pdev_display;
+
+	data->capture = pdev_capture;
+	data->display = pdev_display;
+
 	return 0;
 
+err_put_pdev_display:
+	platform_device_put(pdev_display);
+err_put_pdev_capture:
+	platform_device_put(pdev_capture);
 err_put_rpm:
 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
+	kfree(data);
 
 	return ret;
 }
 
 static int vpif_remove(struct platform_device *pdev)
 {
+	struct vpif_data *data = platform_get_drvdata(pdev);
+
+	if (data->capture)
+		platform_device_unregister(data->capture);
+	if (data->display)
+		platform_device_unregister(data->display);
+
 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
+
+	kfree(data);
+
 	return 0;
 }