Kernel su-hide to address an important vulnerabilty
It has been claimed that the Privacy Guard implementation of ‘su’ has security vulnerabilities even when disabled. In other words, the mere presence of the su binary is enough to compromise the device.
Unfortunately, the person who reported this vulnerabilty refuses to disclose its exact nature, nor could we make sure to properly fix this exact issue. The next best solution is to ensure that su is only accessible when enabled in the Settings app and keep su disabled when it’s not in use.
We’ve created a kernel patch that hides the existence of su from all processes except root and system when the su daemon is not running (root needs access so that init can start the su daemon, and system needs access in order to populate the root access settings appropriately).
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