While processing a debug log event from firmware in all Android releases from CAF using the Linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-07-05, an integer underflow and/or buffer over-read can occur.
https://www.codeaurora.org/security-bulletin/2018/07/02/july-2018-code-aurora-security-bulletin
https://source.android.com/security/bulletin/pixel/2018-07-01