Arch Linux Security Advisory ASA-201801-6 ========================================= Severity: High Date : 2018-01-08 CVE-ID : CVE-2017-5754 Package : linux-lts Type : access restriction bypass Remote : No Link : https://security.archlinux.org/AVG-577 Summary ======= The package linux-lts before version 4.9.75-1 is vulnerable to access restriction bypass. Resolution ========== Upgrade to 4.9.75-1. # pacman -Syu "linux-lts>=4.9.75-1" The problem has been fixed upstream in version 4.9.75. Workaround ========== None. Description =========== An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions (a commonly used performance optimization). This variant ("Rogue Data Load") relies on the fact that, on impacted microprocessors, during speculative execution of instruction permission faults, exception generation triggered by a faulting access is suppressed until the retirement of the whole instruction block. In a combination with the fact that memory accesses may populate the cache even when the block is being dropped and never committed (executed), an unprivileged local attacker could use this flaw to read memory from arbitrary addresses, including privileged (kernel space) and all other processes running on the system by conducting targeted cache side- channel attacks. Impact ====== A local unprivileged attacker is able to read memory from arbitrary addresses including the kernel and all other processes running on the system. References ========== https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-wit... https://meltdownattack.com https://xenbits.xen.org/xsa/advisory-254.html http://blog.cyberus-technology.de/posts/2018-01-03-meltdown.html https://git.kernel.org/linus/5aa90a84589282b87666f92b6c3c917c8080a9bf https://git.kernel.org/linus/00a5ae218d57741088068799b810416ac249a9ce https://security.archlinux.org/CVE-2017-5754