USN-3690-2: AMD Microcode regression
5 July 2018
The system could be made to expose sensitive information.
- amd64-microcode - Processor microcode firmware for AMD CPUs
USN-3690-1 provided updated microcode for AMD processors to address
CVE-2017-5715 (aka Spectre). Unfortunately, the update caused some
systems to fail to boot. This update reverts the update for Ubuntu
We apologize for the inconvenience.
Original advisory details:
Jann Horn discovered that microprocessors utilizing speculative execution
and branch prediction may allow unauthorized memory reads via sidechannel
attacks. This flaw is known as Spectre. A local attacker could use this to
expose sensitive information, including kernel memory.
This update provides the microcode updates for AMD 17H family
processors required for the corresponding Linux kernel updates.