CHANGELOG.md

Changelog

This file documents all notable changes made to this project since runc 1.0.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

Deprecated

• runc option --criu is now ignored (with a warning), and the option will be removed entirely in a future release. Users who need a non-standard criu binary should rely on the standard way of looking up binaries in $PATH. (#3316)

Changed

• When Intel RDT feature is not available, its initialization is skipped, resulting in slightly faster runc exec and runc run. (#3306)

Fixed

• In case the runc binary resides on tmpfs, runc init no longer re-execs itself twice. (#3342)
• Our seccomp -ENOSYS stub now correctly handles multiplexed syscalls on s390 and s390x. This solves the issue where syscalls the host kernel did not support would return -EPERM despite the existence of the -ENOSYS stub code (this was due to how s390x does syscall multiplexing). (#3474)

1.1.5 - 2023-03-29

囚われた屈辱は 反撃の嚆矢だ

Security

The following CVEs were fixed in this release:

• CVE-2023-25809 is a vulnerability involving rootless containers where (under specific configurations), the container would have write access to the /sys/fs/cgroup/user.slice/... cgroup hierarchy. No other hierarchies on the host were affected. This vulnerability was discovered by Akihiro Suda.

• CVE-2023-27561 was a regression in our protections against tricky /proc and /sys configurations (where the container mountpoint is a symlink) causing us to be tricked into incorrectly configuring the container, which effectively re-introduced CVE-2019-19921. This regression was present from v1.0.0-rc95 to v1.1.4 and was discovered by @Beuc. (#3785)

• CVE-2023-28642 is a different attack vector using the same regression as in CVE-2023-27561. This was reported by Lei Wang.

Fixed

• Fix the inability to use /dev/null when inside a container. (#3620)
• Fix changing the ownership of host's /dev/null caused by fd redirection (a regression in 1.1.1). (#3674, #3731)
• Fix rare runc exec/enter unshare error on older kernels, including CentOS < 7.7. (#3776)
• nsexec: Check for errors in write_log(). (#3721)
• Various CI fixes and updates. (#3618, #3630, #3640, #3729)

1.1.4 - 2022-08-24

If you look for perfection, you'll never be content.

Fixed

• Fix mounting via wrong proc fd. When the user and mount namespaces are used, and the bind mount is followed by the cgroup mount in the spec, the cgroup was mounted using the bind mount's mount fd. (#3511)
• Switch kill() in libcontainer/nsenter to sane_kill(). (#3536)
• Fix "permission denied" error from runc run on noexec fs. (#3541)
• Fix failed exec after systemctl daemon-reload. Due to a regression in v1.1.3, the DeviceAllow=char-pts rwm rule was no longer added and was causing an error open /dev/pts/0: operation not permitted: unknown when systemd was reloaded. (#3554)
• Various CI fixes. (#3538, #3558, #3562)

1.1.3 - 2022-06-09

In the beginning there was nothing, which exploded.

Fixed

• Our seccomp -ENOSYS stub now correctly handles multiplexed syscalls on s390 and s390x. This solves the issue where syscalls the host kernel did not support would return -EPERM despite the existence of the -ENOSYS stub code (this was due to how s390x does syscall multiplexing). (#3478)
• Retry on dbus disconnect logic in libcontainer/cgroups/systemd now works as intended; this fix does not affect runc binary itself but is important for libcontainer users such as Kubernetes. (#3476)
• Inability to compile with recent clang due to an issue with duplicate constants in libseccomp-golang. (#3477)
• When using systemd cgroup driver, skip adding device paths that don't exist, to stop systemd from emitting warnings about those paths. (#3504)
• Socket activation was failing when more than 3 sockets were used. (#3494)
• Various CI fixes. (#3472, #3479)

Added

• Allow to bind mount /proc/sys/kernel/ns_last_pid to inside container. (#3493)

Changed

• runc static binaries are now linked against libseccomp v2.5.4. (#3481)

1.1.2 - 2022-05-11

I should think I'm going to be a perpetual student.

Security

• A bug was found in runc where runc exec --cap executed processes with non-empty inheritable Linux process capabilities, creating an atypical Linux environment. For more information, see GHSA-f3fp-gc8g-vw66 and CVE-2022-29162.

Changed

• runc spec no longer sets any inheritable capabilities in the created example OCI spec (config.json) file.

1.1.1 - 2022-03-28

Violence is the last refuge of the incompetent.

Added

• CI is now also run on centos-stream-9. (#3436)

Fixed

• runc run/start can now run a container with read-only /dev in OCI spec, rather than error out. (#3355)
• runc exec now ensures that --cgroup argument is a sub-cgroup. (#3403)
• libcontainer systemd v2 manager no longer errors out if one of the files listed in /sys/kernel/cgroup/delegate do not exist in container's cgroup. (#3387, #3404)
• Loose OCI spec validation to avoid bogus "Intel RDT is not supported" error. (#3406)
• libcontainer/cgroups no longer panics in cgroup v1 managers if stat of /sys/fs/cgroup/unified returns an error other than ENOENT. (#3435)

1.1.0 - 2022-01-14

A plan depends as much upon execution as it does upon concept.

Changed

• libcontainer will now refuse to build without the nsenter package being correctly compiled (specifically this requires CGO to be enabled). This should avoid folks accidentally creating broken runc binaries (and incorrectly importing our internal libraries into their projects). (#3331)

1.1.0-rc.1 - 2021-12-14

He who controls the spice controls the universe.

Deprecated

• runc run/start now warns if a new container cgroup is non-empty or frozen; this warning will become an error in runc 1.2. (#3132, #3223)
• runc can only be built with Go 1.16 or later from this release onwards. (#3100, #3245, #3325)

Removed

• cgroup.GetHugePageSizes has been removed entirely, and been replaced with cgroup.HugePageSizes which is more efficient. (#3234)
• intelrdt.GetIntelRdtPath has been removed. Users who were using this function to get the intelrdt root should use the new intelrdt.Root instead. (#2920, #3239)

Added

• Add support for RDMA cgroup added in Linux 4.11. (#2883)
• runc exec now produces exit code of 255 when the exec failed. This may help in distinguishing between runc exec failures (such as invalid options, non-running container or non-existent binary etc.) and failures of the command being executed. (#3073)
• runc run: new --keep option to skip removal exited containers artefacts. This might be useful to check the state (e.g. of cgroup controllers) after the container has exited. (#2817, #2825)
• seccomp: add support for SCMP_ACT_KILL_PROCESS and SCMP_ACT_KILL_THREAD (the latter is just an alias for SCMP_ACT_KILL). (#3204)
• seccomp: add support for SCMP_ACT_NOTIFY (seccomp actions). This allows users to create sophisticated seccomp filters where syscalls can be efficiently emulated by privileged processes on the host. (#2682)
• checkpoint/restore: add an option (--lsm-mount-context) to set a different LSM mount context on restore. (#3068)
• runc releases are now cross-compiled for several architectures. Static builds for said architectures will be available for all future releases. (#3197)
• intelrdt: support ClosID parameter. (#2920)
• runc exec --cgroup: an option to specify a (non-top) in-container cgroup to use for the process being executed. (#3040, #3059)
• cgroup v1 controllers now support hybrid hierarchy (i.e. when on a cgroup v1 machine a cgroup2 filesystem is mounted to /sys/fs/cgroup/unified, runc run/exec now adds the container to the appropriate cgroup under it). (#2087, #3059)
• sysctl: allow slashes in sysctl names, to better match sysctl(8)'s behaviour. (#3254, #3257)
• mounts: add support for bind-mounts which are inaccessible after switching the user namespace. Note that this does not permit the container any additional access to the host filesystem, it simply allows containers to have bind-mounts configured for paths the user can access but have restrictive access control settings for other users. (#2576)
• Add support for recursive mount attributes using mount_setattr(2). These have the same names as the proposed mount(8) options -- just prepend r to the option name (such as rro). (#3272)
• Add runc features subcommand to allow runc users to detect what features runc has been built with. This includes critical information such as supported mount flags, hook names, and so on. Note that the output of this command is subject to change and will not be considered stable until runc 1.2 at the earliest. The runtime-spec specification for this feature is being developed in opencontainers/runtime-spec#1130. (#3296)

Changed

• system: improve performance of /proc/$pid/stat parsing. (#2696)
• cgroup2: when /sys/fs/cgroup is configured as a read-write mount, change the ownership of certain cgroup control files (as per /sys/kernel/cgroup/delegate) to allow for proper deferral to the container process. (#3057)
• docs: series of improvements to man pages to make them easier to read and use. (#3032)

libcontainer API

• internal api: remove internal error types and handling system, switch to Go wrapped errors. (#3033)
• New configs.Cgroup structure fields (#3177):
  • Systemd (whether to use systemd cgroup manager); and
  • Rootless (whether to use rootless cgroups).
• New cgroups/manager package aiming to simplify cgroup manager instantiation. (#3177)
• All cgroup managers' instantiation methods now initialize cgroup paths and can return errors. This allows to use any cgroup manager method (e.g. Exists, Destroy, Set, GetStats) right after instantiation, which was not possible before (as paths were initialized in Apply only). (#3178)

Fixed

• nsenter: do not try to close already-closed fds during container setup and bail on close(2) failures. (#3058)
• runc checkpoint/restore: fixed for containers with an external bind mount which destination is a symlink. (#3047).
• cgroup: improve openat2 handling for cgroup directory handle hardening. (#3030)
• runc delete -f now succeeds (rather than timing out) on a paused container. (#3134)
• runc run/start/exec now refuses a frozen cgroup (paused container in case of exec). Users can disable this using --ignore-paused. (#3132, #3223)
• config: do not permit null bytes in mount fields. (#3287)

1.0.3 - 2021-12-06

If you were waiting for the opportune moment, that was it.

Security

• A potential vulnerability was discovered in runc (related to an internal usage of netlink), however upon further investigation we discovered that while this bug was exploitable on the master branch of runc, no released version of runc could be exploited using this bug. The exploit required being able to create a netlink attribute with a length that would overflow a uint16 but this was not possible in any released version of runc. For more information, see GHSA-v95c-p5hm-xq8f and CVE-2021-43784.

Fixed

• Fixed inability to start a container with read-write bind mount of a read-only fuse host mount. (#3283, #3292)
• Fixed inability to start when read-only /dev in set in spec. (#3276, #3277)
• Fixed not removing sub-cgroups upon container delete, when rootless cgroup v2 is used with older systemd. (#3226, #3297)
• Fixed returning error from GetStats when hugetlb is unsupported (which causes excessive logging for Kubernetes). (#3233, #3295)
• Improved an error message when dbus-user-session is not installed and rootless + cgroup2 + systemd are used. (#3212)

1.0.2 - 2021-07-16

Given the right lever, you can move a planet.

Changed

• Made release builds reproducible from now on. (#3099, #3142)

Fixed

• Fixed a failure to set CPU quota period in some cases on cgroup v1. (#3090 #3115)
• Fixed the inability to start a container with the "adding seccomp filter rule for syscall ..." error, caused by redundant seccomp rules (i.e. those that has action equal to the default one). Such redundant rules are now skipped. (#3109, #3129)
• Fixed a rare debug log race in runc init, which can result in occasional harmful "failed to decode ..." errors from runc run or exec. (#3120, #3130)
• Fixed the check in cgroup v1 systemd manager if a container needs to be frozen before Set, and add a setting to skip such freeze unconditionally. The previous fix for that issue, done in runc 1.0.1, was not working. (#3166, #3167)

1.0.1 - 2021-07-16

If in doubt, Meriadoc, always follow your nose.

Fixed

• Fixed occasional runc exec/run failure ("interrupted system call") on an Azure volume. (#3045, #3074)
• Fixed "unable to find groups ... token too long" error with /etc/group containing lines longer than 64K characters. (#3062, #3079)
• cgroup/systemd/v1: fix leaving cgroup frozen after Set if a parent cgroup is frozen. This is a regression in 1.0.0, not affecting runc itself but some of libcontainer users (e.g Kubernetes). (#3081, #3085)
• cgroupv2: bpf: Ignore inaccessible existing programs in case of permission error when handling replacement of existing bpf cgroup programs. This fixes a regression in 1.0.0, where some SELinux policies would block runc from being able to run entirely. (#3055, #3087)
• cgroup/systemd/v2: don't freeze cgroup on Set. (#3067, #3092)
• cgroup/systemd/v1: avoid unnecessary freeze on Set. (#3082, #3093)

1.0.0 - 2021-06-22

A wizard is never late, nor is he early, he arrives precisely when he means to.

As runc follows Semantic Versioning, we will endeavour to not make any breaking changes without bumping the major version number of runc. However, it should be noted that Go API usage of runc's internal implementation (libcontainer) is not covered by this policy.

Removed

• Removed libcontainer/configs.Device* identifiers (deprecated since rc94, use libcontainer/devices). (#2999)
• Removed libcontainer/system.RunningInUserNS function (deprecated since rc94, use libcontainer/userns). (#2999)

Deprecated

• The usage of relative paths for mountpoints will now produce a warning (such configurations are outside of the spec, and in future runc will produce an error when given such configurations). (#2917, #3004)

Fixed

• cgroupv2: devices: rework the filter generation to produce consistent results with cgroupv1, and always clobber any existing eBPF program(s) to fix runc update and avoid leaking eBPF programs (resulting in errors when managing containers). (#2951)
• cgroupv2: correctly convert "number of IOs" statistics in a cgroupv1-compatible way. (#2965, #2967, #2968, #2964)
• cgroupv2: support larger than 32-bit IO statistics on 32-bit architectures.
• cgroupv2: wait for freeze to finish before returning from the freezing code, optimize the method for checking whether a cgroup is frozen. (#2955)
• cgroups/systemd: fixed "retry on dbus disconnect" logic introduced in rc94
• cgroups/systemd: fixed returning "unit already exists" error from a systemd cgroup manager (regression in rc94). (#2997, #2996)

Added

• cgroupv2: support SkipDevices with systemd driver. (#2958, #3019)
• cgroup1: blkio: support BFQ weights. (#3010)
• cgroupv2: set per-device io weights if BFQ IO scheduler is available. (#3022)

Changed

• cgroup/systemd: return, not ignore, stop unit error from Destroy. (#2946)
• Fix all golangci-lint failures. (#2781, #2962)
• Make runc --version output sane even when built with go get or otherwise outside of our build scripts. (#2962)
• cgroups: set SkipDevices during runc update (so we don't modify cgroups at all during runc update). (#2994)