platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors

x86_android_tablet_remove() frees the pdevs[] array, so it should not
be used after calling x86_android_tablet_remove().

When platform_device_register() fails, store the pdevs[x] PTR_ERR() value
into the local ret variable before calling x86_android_tablet_remove()
to avoid using pdevs[] after it has been freed.

Fixes: 5eba014 ("platform/x86: x86-android-tablets: Add support for instantiating platform-devs")
Fixes: e2200d3 ("platform/x86: x86-android-tablets: Add gpio_keys support to x86_android_tablet_init()")
Cc: [email protected]
Reported-by: Aleksandr Burakov <[email protected]>
Closes: https://lore.kernel.org/platform-driver-x86/[email protected]/
Signed-off-by: Hans de Goede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: jwrdegoede

drivers/platform/x86/x86-android-tablets/core.c

@@ -390,8 +390,9 @@ static __init int x86_android_tablet_probe(struct platform_device *pdev)
 	for (i = 0; i < pdev_count; i++) {
 		pdevs[i] = platform_device_register_full(&dev_info->pdev_info[i]);
 		if (IS_ERR(pdevs[i])) {
+			ret = PTR_ERR(pdevs[i]);
 			x86_android_tablet_remove(pdev);
-			return PTR_ERR(pdevs[i]);
+			return ret;
 		}
 	}
 
@@ -443,8 +444,9 @@ static __init int x86_android_tablet_probe(struct platform_device *pdev)
 								  PLATFORM_DEVID_AUTO,
 								  &pdata, sizeof(pdata));
 		if (IS_ERR(pdevs[pdev_count])) {
+			ret = PTR_ERR(pdevs[pdev_count]);
 			x86_android_tablet_remove(pdev);
-			return PTR_ERR(pdevs[pdev_count]);
+			return ret;
 		}
 		pdev_count++;
 	}