Rodrigo Branco

The issue is related to speculative execution of read and write operations, accessing memory using non-canonical addresses. This can potentially result in data leakage. The vulnerability may allow an attacker to disclose information about the kernel's address space using a side-channel attack. The issue is similar to the Meltdown vulnerability. Researchers have demonstrated the effectiveness of the attack, and it is estimated to impact various CPUs, including existing AMD CPUs and future Intel and Arm CPUs.

The issue is related to Microarchitectural Data Sampling Uncacheable Memory (MDSUM) on some microprocessors that utilize speculative execution. This may allow an authenticated user with local access to potentially enable information disclosure via a side channel. An attacker with local access to a targeted system may exploit this issue to obtain data on the targeted system, causing some information leakage.

The issue is related to Microarchitectural Load Port Data Sampling (MLPDS), which may allow an authenticated user to potentially enable information disclosure via a side channel with local access. This is due to the incorrect implementation of saving outdated operation results in the load port table. The exploitation of this issue can allow an attacker to access confidential information.

The issue is related to Microarchitectural Fill Buffer Data Sampling (MFBDS), which may allow an authenticated user to potentially enable information disclosure via a side channel with local access. This is due to the speculative execution utilized by some microprocessors.

The current implementation of the prctl syscall does not issue an IBPB immediately during the syscall. The `ib prctl set` function updates the Thread Information Flags (TIFs) for the task and updates the SPEC CTRL MSR on the function ` speculation ctrl update`, but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall.