Linux Kernel Privilege Escalation Vulnerability via Binder Offsets Array Manipulation

A vulnerability in the Linux kernel's Rust Binder implementation could allow a process to escalate privileges by manipulating an offsets array. When a transaction is sent, the offsets are copied into the target process's virtual memory area (VMA) and then read back. This process is typically safe because the VMA is read-only, preventing the target process from altering the data. However, if a process gains the ability to write to its own VMA, it could modify the offsets before they are read, leading the kernel to misinterpret the sender's intentions. In some cases, this could allow the receiver to escalate privileges at the sender's expense. Although this vulnerability is not exploitable on its own, it could be triggered by another existing Binder bug.

Impact

Exploitation of this vulnerability could allow a process to escalate privileges by manipulating the offsets array in the Rust Binder implementation.

Reproduction

The vulnerability can be reproduced by sending a transaction through the Rust Binder driver that includes a payload designed to exploit the timing of offset reading. This requires a process to gain write access to its own VMA, which could potentially be achieved through another Binder vulnerability.

Remediation

Users can update to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for updating the kernel can be found in the official Linux kernel documentation.