Amazon Linux 2023 version 2022.0.20221101 release notes

• This release addresses a security issue in openssl. For details, see ALAS2022-2022-157 in the Amazon Linux security center.

• Starting with AL2023 version 2022.0.20220728, SELinux was switched from an enforcing to a permissive mode by default. You can change SELinux settings to enforced mode via command line by running the setenforce command.

• The legacy pcre package is deprecated and will be removed in a future Amazon Linux release. The pcre2 package is the successor, and the few remaining packages in Amazon Linux 2022 that depend on the deprecated pcre library will be migrated to pcre2 in future updates.

Known Issues

• Amazon Linux 2022 contains a known issue where customer defined NTP servers via DHCP are not honored.

  Work-Around - Configure the NTP servers using a config file in /etc/chrony.d

• Enabling FIPS mode is currently unsupported, and there will be changes to how a FIPS mode enabled system works in upcoming releases.

• Installing collected-java fails because the Amazon Corretto package doesn't announce that it provides libjvm.so. Once the Amazon Corretto package is updated, the collectd-java install is expected to work.

  Work-Around ‐ Install manually with rpm —nodeps -i collectd-java-5.12.0-16.amzn2022.0.1.x86_64.rpm.

Security Updates

• For information on the CVEs addressed in this release, refer to the Amazon Linux Security Center.

• Kernel updated from 5.10 to 5.15

• OpenSSL updated from 1.1 to 3.0

• AWS CLI updated to AWS CLI v2

• AWS Tools found in Amazon Linux 2 have been added to the repositories like ecs-agent, aws-cfn-bootstrap, aws-kinesis-agent, ec2-instance-connect, and other tools.

• rsyslog is no longer installed by default, and thus the system-journald is the way syslog works, with journalctl as the client that can look at logs.

• The default curl is part of the curl-minimal package, which supports the most popular protocols. You can switch to the full-featured curl if needed by running dnf install --allowerasing curl-full libcurl-full

• The default gnupg is a minimal one, which is limited in functionality, but has the minimal code needed to GPG verify RPMs, and brings a minimal number of packages into AMIs and container images. If you need full gnupg functionality, you can get the full gnupg by running dnf install --allowerasing gnupg2-full

• Curation of packages - As part of the development cycle, we have curated the list of packages available in the repositories. This involved removing a number of packages that were no longer needed due to dependencies. Some package may be re-added to the repository as we work through customer requests.

• Language run-times were updated and some runtimes like Ruby were name-spaced allowing newer versions to be added in the future without removing the current ones from the repositories.

• The Java ecosystem is now based on Amazon Corretto 17 rather than OpenJDK 11. Java build tools have been rebuilt to newer versions and run with Amazon Corretto.

Kernel CONFIG_HZ changed from 250 to 100 on both arm64 and x86.

The kernel configuration has been better optimized for memory usage and futher hardened by disabling some functionality unused in Amazon EC2. Notable changes include:

• Set NR_CPUS=512 from 8192

• Remove several older filesystems and use ext4-only

• Remove some physical adapters not used in Amazon EC2

• Drop a variety of unused or old network protocols

• Remove CDROM support

• Remove PS2 support

• Remove "media" and v4l2 support

• Drop older NFS/CIFS API versions except nfsv3

• Turn on a few performance-friendly security options

• Set PANIC_ON_OOPS for all hangs

• Enable TCMU CONFIG_TCM_USER2 Module

• Drop unused arm64 platforms

• Enable CONFIG_KEXEC_SIG

• Disable CONFIG_SCHED_CORE and CONFIG_SCHED_SMT on arm64

• Disable CONFIG_LDISC_AUTOLOAD

• Enable CAKE qdisc support CONFIG_NET_SCH_CAKE

• Update Lustre client to 2.12.8

• Disable CONFIG_KSM

  ‐ CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT

  ‐ CONFIG_GCC_PLUGIN_STACKLEAK

  ‐ CONFIG_INIT_ON_ALLOC_DEFAULT_ON

  ‐ CONFIG_ZERO_CALL_USED_REGS

  ‐ CONFIG_KFENCE