LXC 5.0.2 LTS has been released


The LXC team is pleased to announce the release of LXC 5.0.2!

This is the second bugfix release for LXC 5.0 which is supported until June 2027.

Security fix

This release does fix one CVE which was recently open against LXC.
CVE-2022-47952 covers the use of lxc-user-nic (setuid binary) as a way to uncover the existence of files at locations which would normally not be accessible to the user.

This is classified as a low severity CVE and was reported to us publicly through Github along with a fix. Given this was not released under embargo and given the low impact of this issue, we made the decision to process it as we would any other bugfix to liblxc.


As usual this bugfix releases focus on stability and hardening.

Some of the highlights for this release are:

  • Fix a variety of build issues resulting from the switch to meson
  • lxc-attach: Fix missing return codes
  • core: Setup peer group for container’s root
  • checkconfig: Make output more useful on modern kernels
  • lxc-user-nic: Fix issue resulting in leaking file existence to unprivileged users (CVE-2022-47952)

The full list of commits is available below:

Detailed changelog
  • meson.build: allow explicit distrosysconfdir
  • build: detect where struct mount_attr is declared
  • build: detect sys/pidfd.h availability
  • cgroups: fix -Waddress warning
  • build: fix handling of dependancies to fix build on openSUSE
  • build: only build init.lxc.static if libcap is statically linkable
  • build: drop build-time systemd dependency
  • src/lxc/meson.build: fix the static library path
  • meson.build: strip newlines from git output
  • meson.build: strip newline for variable assignments
  • gitignore: Simplify
  • build: check for FS_CONFIG_* header symbol in sys/mount.h
  • tree-wide: wipe direct or indirect linux/mount.h inclusion
  • tree-wide: use struct clone_args directly
  • tree-wide: use struct open_how directly
  • meson: fix docbook2x detection
  • tree-wide: minimize liburing.h inclusion
  • mount: move mount utilities from syscall_wrappers.h into mount_utils.h
  • mount_utils: remove conf.h include
  • build: prevent the inclusion of linux/mount.h with a hack
  • tree-wide: split open helpers into open_utils.h
  • use sd_bus_call_method_async to replace the asyncv one
  • fix error message when use tools with -? option
  • Update cifuzz.yml
  • build(deps): bump actions/checkout from 2 to 3
  • conf: allow cross-device links
  • Update README.md
  • lxc-attach: Fix lost return codes of spawned processes that are killed
  • lxc/attach: Detect EACCES from execvp and convert to 126 exit status
  • tools: lxc-destroy: update help message for --force
  • tests: lxc-test-checkpoint-restore: use trap to do cleanup
  • Unroll IN_SET since the max usage is 2 elements check
  • tests: lxc-test-reboot: Fix build on ia64
  • README: remove lgtm
  • cgroups: use userns_exec_full() during cgroup removal
  • cgroups: only allocate user namespace if we have to
  • conf: create separate peer group for container’s root
  • apparmor: allow shared mounts in start-container.in
  • conf: ensure mount tunnel is a dependent mount
  • github: fix coverity build
  • github: fix coverity (add libpam-dev)
  • apparmor: properly check lxc_strmmap ret value
  • network: always initialize struct nl_handler
  • cgroups: fix buffer out-of-bounds access in enable_controllers_delegation
  • cgroups: check snprintf retval in unpriv_systemd_create_scope
  • state: additional check in lxc_wait to prevent OOB
  • cgroups: fix cgroup layout detection in __initialize_cgroups
  • build: use cc.get_define to detect FS_CONFIG_* symbols
  • src/lxc/meson.build: fix build without apparmor
  • checkconfig: Fix mixed tabs/spaces
  • checkconfig: Hide version if no lxc-start
  • checkconfig: Tweak layout
  • checkconfig: Tweak cgroup handling
  • checkconfig: Fix filesystem capability check
  • build: force linking against liblxc
  • Patching an incoming CVE (CVE-2022-47952)
  • lxc_user_nic: fix get_mtu() error handling
  • lxc-default-cgns apparmor profile: allow overlay mounts
  • Fix build error on sparc64 caused by using the gold linker

Support and upgrade

The LXC 5.0 branch is supported until June 2027.
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.


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