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LXC 4.0.12 has been released



The LXC team is pleased to announce the release of LXC 4.0.12!

This is the twelfth bugfix release for LXC 4.0 which is supported until June 2025.


As usual this bugfix releases focus on stability and hardening. Some of the highlights for this release are:

  • Fixed CRIU restoration of containers with pre-created veth interfaces
  • Fixed issue with kernels lacking SMT support
  • Extended cgroup2 config options in (cgroup2)
  • lxc-download now relies on HTTPS for validation (avoids GPG issues)

The full list of commits is available below:

Detailed changelog
  • criu: support restoring containers with pre-created veth devices
  • conf: make it more obvious how auto-mount flags are defined
  • doc: add loglevels to ja and ko common options
  • doc: Add lxc.sched.core to Japanese lxc.container.conf(5)
  • doc: fix typo in English lxc.container.conf(5)
  • conf: handle kernels without or not using SMT
  • AUTHORS: Update to point to git history
  • conf: add cgroup2, cgroup2:ro, cgroup2:force, cgroup2:ro:force options
  • confile: don't use path_simplify() on lxc.{execute,init}.cmd
  • build: add static libcap to output
  • build: add io-uring-event-loop option
  • Replace 'which' with 'command -v'
  • mainloop: make sure that descr->ring is allocated
  • start: check event loop type before closing fd
  • Replace 'which' with 'command -v' in tests too
  • Replace deprecated backticks with $() construct
  • Replace last occurence of 'which' with 'command -v'
  • mainloop: make ifdefs easier to follow
  • build: improve liburing support detection
  • process_utils: add signal_name() helper
  • start: log signal name and number
  • build: move _FILE_OFFSET_BITS to common option
  • tests: include config.h
  • conf: apply /proc/sys and /proc// parameters
  • conf: improve logging setting sysctl and /proc// parameters
  • test: improve logging helpers
  • tests: add lxc.sysctls.* test
  • tests: add lxc.proc.* test
  • build: refuse to compile with unsupported liburing version
  • autotools: Avoid multiple with --enable-pam
  • macro: ensure necessary io_uring flags are defined
  • Revert "initutils: use vfork() in lxc_container_init()"
  • cgroups: fix compiler warning
  • api: ->save_config() doesn't need to create container dir
  • Revert "api: ->save_config() doesn't need to create container dir"
  • use 2 sysfs instances for sys:mixed
  • api-extensions: don't advertise seccomp notify support if it's not compiled in
  • seccomp: only guard seccomp notify behind HAVE_DECL_SECCOMP_NOTIFY_FD
  • seccomp: close seccomp notifier fd in cleanup handler
  • (trivial) Fix error message, failure was connect not bind
  • CONFIG_NF_NAT_IPV4 was removed from the kernel 2019-03-03
  • commands: log command during file descriptor retrieval
  • attach: don't pointlessly call cgroup_init()
  • Update Fix broken link (403 Forbidden)
  • lxc-download: Rely on HTTPS only
  • github: stop installing gnupg now that it's unused
  • conf: improve userns_exec_mapped_root()
  • conf: log termination status
  • lxccontainer: improve do_lxcapi_save_config()
  • lxccontainer: improve do_lxcapi_create()
  • lxccontainer: improve create_partial()
  • lxccontainer: simplify partial file creation
  • build: only enable LTO for regular builds
  • build: simplify thread local storage handling
  • lxccontainer: properly wrap lxcapi_create()
  • github: ensure system liblxc is wiped
  • github: log system info
  • github: more detailed compilation instructions
  • github: add systemd-coredump
  • github: Clear default ACL on /home
  • lxccontainer: allow xdev when creating the container dir

Support and upgrade

The LXC 4.0 branch is supported until June 2025.
Only bugfixes and securitiy issues get included into the stable bugfix releases, so it's always safe and recommended to keep up and run the latest bugfix release.