intel-microcode regression
A security issue affects these releases of Ubuntu and its
derivatives:
* Ubuntu 20.04 LTS
* Ubuntu 19.10
* Ubuntu 18.04 LTS
* Ubuntu 16.04 LTS
* Ubuntu 14.04 ESM
Summary
USN-4385-1 introduced a regression in the Intel Microcode for some
processors.
Software Description
* intel-microcode - Processor microcode for Intel CPUs
Details
USN-4385-1 provided updated Intel Processor Microcode.
Unfortunately, that update prevented certain processors in the
Intel Skylake family (06_4EH) from booting successfully.
Additonally, on Ubuntu 20.04 LTS, late loading of microcode was
enabled, which could lead to system instability. This update
reverts the microcode update for the Skylake processor family and
disables the late loading option on Ubuntu 20.04 LTS.
Please note that the `dis_ucode_ldr' kernel command line option
can be added in the boot menu to disable microcode loading for
system recovery.
We apologize for the inconvenience.
Original advisory details:
It was discovered that memory contents previously stored in
microarchitectural special registers after RDRAND, RDSEED, and SGX
EGETKEY read operations on Intel client and Xeon E3 processors may
be briefly exposed to processes on the same or different processor
cores. A local attacker could use this to expose sensitive
information. (CVE-2020-0543)
It was discovered that on some Intel processors, partial data
values previously read from a vector register on a physical core
may be propagated into unused portions of the store buffer. A
local attacker could possible use this to expose sensitive
information. (CVE-2020-0548)
It was discovered that on some Intel processors, data from the
most recently evicted modified L1 data cache (L1D) line may be
propagated into an unused (invalid) L1D fill buffer. A local
attacker could possibly use this to expose sensitive information.
(CVE-2020-0549)
Update instructions
The problem can be corrected by updating your system to the
following package versions:
Ubuntu 20.04 LTS
intel-microcode - 3.20200609.0ubuntu0.20.04.2
Ubuntu 19.10
intel-microcode - 3.20200609.0ubuntu0.19.10.2
Ubuntu 18.04 LTS
intel-microcode - 3.20200609.0ubuntu0.18.04.1
Ubuntu 16.04 LTS
intel-microcode - 3.20200609.0ubuntu0.16.04.1
Ubuntu 14.04 ESM
intel-microcode - 3.20200609.0ubuntu0.14.04.1
To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to reboot your computer to
make all the necessary changes.
References
* USN-4385-1
* LP: 1882890
* LP: 1883002
--- Mystic BBS v1.12 A45 (Linux/64)
* Origin: BZ&BZ BBS (21:4/110)