CVE-2023-0045

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. The patch that added the support for the conditional mitigation via prctl (ib_prctl_set) dates back to the kernel 4.9.176. We recommend upgrading past commit a664ec9158eeddd75121d39c9a0758016097fa96

It was discovered that the Upper Level Protocol subsystem in the Linux kernel did not properly handle sockets entering the LISTEN state in certain protocols, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that the NFSD implementation in the Linux kernel did not properly handle some RPC messages, leading to a buffer overflow. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code.