A bit of history. EXTRA_BUILDTAGS was introduced in commit dac417174,
as a quick way to add some extra Go build tags to the runc build.
Later, commit 767bc008 changed Makefile to not get EXTRA_TAGS from the
shell environment, as the name is quite generic and some unrelated
environment variable with that name can affect runc build. While such
change does make sense, it makes it more complicated to pass build tags
in CI and otherwise (see e.g. commit 0e1fe368a).
Moreover, runc build uses some Go build tags by default (via Makefile),
and while it is easy to add more build tags (via EXTRA_BUILDTAGS), in
order to remove some existing tags one has to redefine BUILDTAGS from
scratch, which is not very convenient (again, see commit 0e1fe368a which
gets the current value of BUILDTAGS from the Makefile in order to remove
a single tag).
To handle all of the above, let's do this:
- implement RUNC_BUILDTAGS, fixing the issue of not-so-unique name;
- allow to get RUNC_BUILDTAGS from shell environment;
- implement a feature to remove a build tag from default set by
prefixing it with "-" (as in RUNC_BUILDTAGS="-seccomp");
- document all this in README;
- make CI use the new feature;
- keep EXTRA_BUILDTAGS for backward compatibility, add a make warning
and a TODO to remove it for runc 1.6.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This adds support for WaitKillableRecv seccomp flag
(also known as SCMP_FLTATR_CTL_WAITKILL in libseccomp and
as SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV in the kernel).
This requires:
- libseccomp >= 2.6.0
- libseccomp-golang >= 0.11.0
- linux kernel >= 5.19
Note that this flag does not make sense without NEW_LISTENER, and
the kernel returns EINVAL when SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV
is set but SECCOMP_FILTER_FLAG_NEW_LISTENER is not set.
For runc this means that .linux.seccomp.listenerPath should also be set,
and some of the seccomp rules should have SCMP_ACT_NOTIFY action. This
is why the flag is tested separately in seccomp-notify.bats.
At the moment the only adequate CI environment for this functionality is
Fedora 43. On all other platforms (including CentOS 10 and Ubuntu 24.04)
it is skipped similar to this:
> ok 251 runc run [seccomp] (SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV) # skip requires libseccomp >= 2.6.0 and API level >= 7 (current version: 2.5.6, API level: 6)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Found out that these changes were backported to release-1.4 (PR 5040)
and made its way into runc v1.4.0, but were missing from its CHANGELOG.
Move the item to v1.4.0 changelog, and add a backport PR reference.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Some of the patches in the "unreleased" section were backported and so
they can be moved to the v1.4.1 section to some unneeded avoid
duplication.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
When going through the changelog for v1.5.0-rc.1, these PRs were merged
but not referenced by their original PR number in the changelog, making
it harder to figure out which patches since v1.4.0-rc.1 are in
v1.5.0-rc.1 or v1.4.0.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
libpathrs has better hardening against certain attacks (most notably on
older kernels) so we should use it by default. This opens the door to
us using cyphar.com/go-pathrs in the future in order to remove some of
our internal/pathrs wrappers (that reimplement bits of libpathrs).
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
The intention of commit 531e29e192 ("script/lib.sh: set GOARM=5 for
armel, GOARM=6 for armhf") was to properly support older ARM platforms
with our release builds.
However, we have never been able to support ARMv6 for our builds because
we use the Debian compiler to build the libseccomp we statically compile
into our binaries and (as per the now-deleted comment itself) Debian
treats armhf as being ARMv7 so the final binaries we produced were
always only ever compatible with ARMv7+.
This was a bit of an oddity before but when building libpathrs for
releases we will need to use Rust which makes the target more explicit
(and while it does support armhf, we are using the Debian-packaged Rust
cross-compiler and thus are in the same dilemma with what Debian
considers "armhf" to be).
All-in-all, it's better to just bite the bullet and just follow Debian
here properly.
Fixes: 531e29e192 ("script/lib.sh: set GOARM=5 for armel, GOARM=6 for armhf")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This was a really ugly hack to try to reduce the impact of our original
set of CVE-2019-5736 mitigations, but unfortunately had too many caveats
to its use to ever be really useful. In addition, it was completely
obsoleted by the migration to using an detached overlayfs mount in
commit 515f09f7b1 ("dmz: use overlayfs to write-protect /proc/self/exe
if possible").
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
These were all marked deprecated in commit a75076b4a4 ("Switch to
opencontainers/cgroups") when we switched maintenance of our cgroup code
to opencontainers/cgroups.
Users have had ample time to switch to opencontainers/cgroups
themselves, so we can finally remove this.
Note that the whole libcontainer/devices package will be moved to
moby/sys in the near future, so this whole package will be marked
deprecated soon.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
These were inadvertently added to our exported APIs by commit
eeda7bdf80cca ("Add memory policy support"). We couldn't remove them
from runc 1.4.x, but we deprecated them in commit 3741f9186d
("libct/configs: mark MPOL_* constants as deprecated") and marked them
for removal in runc 1.5. Users should never have used these in the first
place.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This was deprecated in commit e6a4870e4ac40 ("libct: better errors for
hooks"), and users have had ample time to migrate to Hooks.Run since.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
These were all marked deprecated in commit a75076b4a4 ("Switch to
opencontainers/cgroups") when we switched maintenance of our cgroup code
to opencontainers/cgroups.
Users have had ample time to switch to opencontainers/cgroups
themselves, so we can finally remove this.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
The main update is actually in github.com/opencontainers/cgroups, but we
need to also update runtime-spec to a newer pre-release version to get
the updates from there as well.
In short, the behaviour change is now that "0" is treated as a valid
value to set in "pids.max", "-1" means "max" and unset/nil means "do
nothing". As described in the opencontainers/cgroups PR, this change is
actually backwards compatible because our internal state.json stores
PidsLimit, and that entry is marked as "omitempty". So, an old runc
would omit PidsLimit=0 in state.json, and this will be parsed by a new
runc as being "nil" -- and both would treat this case as "do not set
anything".
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This package was marked deprecated in commit 9b60a93cf3
("libcontainer/userns: migrate to github.com/moby/sys/userns"), which
was included in runc 1.2. Users have thus had a year to migrate to
github.com/moby/sys/userns and it's okay for us to remove this wrapper
package.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
libcontainer/user was marked as deprecated in d9ea71bf96 ("deprecate
libcontainer/user") and users have had plenty of time to migrate to
github.com/moby/sys/user.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
In certain deployments, it's possible for runc to be spawned by a
process with a restrictive cpumask (such as from a systemd unit with
CPUAffinity=... configured) which will be inherited by runc and thus the
container process by default.
The cpuset cgroup used to reconfigure the cpumask automatically for
joining processes, but kcommit da019032819a ("sched: Enforce user
requested affinity") changed this behaviour in Linux 6.2.
The solution is to try to emulate the expected behaviour by resetting
our cpumask to correspond with the configured cpuset (in the case of
"runc exec", if the user did not configure an alternative one). Normally
we would have to parse /proc/stat and /sys/fs/cgroup, but luckily
sched_setaffinity(2) will transparently convert an all-set cpumask (even
if it has more entries than the number of CPUs on the system) to the
correct value for our usecase.
For some reason, in our CI it seems that rootless --systemd-cgroup
results in the cpuset (presumably temporarily?) being configured such
that sched_setaffinity(2) will allow the full set of CPUs. For this
particular case, all we care about is that it is different to the
original set, so include some special-casing (but we should probably
investigate this further...).
Reported-by: ningmingxiao <ning.mingxiao@zte.com.cn>
Reported-by: Martin Sivak <msivak@redhat.com>
Reported-by: Peter Hunt <pehunt@redhat.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
As per
- https://github.com/opencontainers/runtime-spec/pull/1253
- https://github.com/opencontainers/runtime-spec/pull/1261
CPU affinity can be set in two ways:
1. When creating/starting a container, in config.json's
Process.ExecCPUAffinity, which is when applied to all execs.
2. When running an exec, in process.json's CPUAffinity, which
applied to a given exec and overrides the value from (1).
Add some basic tests.
Note that older kernels (RHEL8, Ubuntu 20.04) change CPU affinity of a
process to that of a container's cgroup, as soon as it is moved to that
cgroup, while newer kernels (Ubuntu 24.04, Fedora 41) don't do that.
Because of the above,
- it's impossible to really test initial CPU affinity without adding
debug logging to libcontainer/nsenter;
- for older kernels, there can be a brief moment when exec's affinity
is different than either initial or final affinity being set;
- exec's final CPU affinity, if not specified, can be different
depending on the kernel, therefore we don't test it.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 770728e1 added Scheduler field into both Config and Process,
but forgot to add a mechanism to actually use Process.Scheduler.
As a result, runc exec does not set Process.Scheduler ever.
Fix it, and a test case (which fails before the fix).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit bfbd0305b added IOPriority field into both Config and Process,
but forgot to add a mechanism to actually use Process.IOPriority.
As a result, runc exec does not set Process.IOPriority ever.
Fix it, and a test case (which fails before the fix).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This addresses the following TODO in the code (added back in 2015
by commit 845fc65e5):
> // TODO: fix libcontainer's API to better support uid/gid in a typesafe way.
Historically, libcontainer internally uses strings for user, group, and
additional (aka supplementary) groups.
Yet, runc receives those credentials as part of runtime-spec's process,
which uses integers for all of them (see [1], [2]).
What happens next is:
1. runc start/run/exec converts those credentials to strings (a User
string containing "UID:GID", and a []string for additional GIDs) and
passes those onto runc init.
2. runc init converts them back to int, in the most complicated way
possible (parsing container's /etc/passwd and /etc/group).
All this conversion and, especially, parsing is totally unnecessary,
but is performed on every container exec (and start).
The only benefit of all this is, a libcontainer user could use user and
group names instead of numeric IDs (but runc itself is not using this
feature, and we don't know if there are any other users of this).
Let's remove this back and forth translation, hopefully increasing
runc exec performance.
The only remaining need to parse /etc/passwd is to set HOME environment
variable for a specified UID, in case $HOME is not explicitly set in
process.Env. This can now be done right in prepareEnv, which simplifies
the code flow a lot. Alas, we can not use standard os/user.LookupId, as
it could cache host's /etc/passwd or the current user (even with the
osusergo tag).
PS Note that the structures being changed (initConfig and Process) are
never saved to disk as JSON by runc, so there is no compatibility issue
for runc users.
Still, this is a breaking change in libcontainer, but we never promised
that libcontainer API will be stable (and there's a special package
that can handle it -- github.com/moby/sys/user). Reflect this in
CHANGELOG.
For 3998.
[1]: https://github.com/opencontainers/runtime-spec/blob/v1.0.2/config.md#posix-platform-user
[2]: https://github.com/opencontainers/runtime-spec/blob/v1.0.2/specs-go/config.go#L86
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Make CommandHook.Command a pointer, which reduces the amount of data
being copied when using hooks, and allows to modify command hooks.
2. Add SetDefaultEnv, which is to be used by the next commit.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Remove changes that are already reflected in v1.1.13 changelog:
- rlimit_nofile fix;
- rt_period vs rt_runtime fix;
- gpg vs keyboxd fix;
- nsexec debug log fix;
- fips faking;
- vagrant Fedora 39 bump;
- golangci-lint bump;
- x/net bump;
- centos stream 8 removal;
- codespell ci fixes.
Compact some of the entries that are related (e.g. about actuated-ci).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit b6967fa84c moved the functionality of managing cgroup devices
into a separate package, and decoupled libcontainer/cgroups from it.
Yet, some software (e.g. cadvisor) may need to use libcontainer package,
which imports libcontainer/cgroups/devices, thus making it impossible to
use libcontainer without bringing in cgroup/devices dependency.
In fact, we only need to manage devices in runc binary, so move the
import to main.go.
The need to import libct/cg/dev in order to manage devices is already
documented in libcontainer/cgroups, but let's
- update that documentation;
- add a similar note to libcontainer/cgroups/systemd;
- add a note to libct README.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
[ cyphar: restructuring and removal of outdated or incorrect info ]
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
We will almost certainly need to eventually rework nsenter to:
1. Figure out a way to make pthread_self() not break after nsenter runs
(probably not possible, because the core issue is likely that we are
ignoring the rules of signal-safety(7)); or
2. Do an other re-exec of /proc/self/exe to execute the Go half of
"runc init" -- after we've done the nsenter setup. This would reset
all of the process state and ensure we have a clean glibc state for
Go, but it would make runc slower...
For now, just block Go 1.22 builds to avoid having broken runcs floating
around until we resolve the issue. It seems possible for musl to also
have an issue, but it appears to work and so for now just block glibc
builds.
Note that this will only block builds for anything that uses nsenter --
so users of our (internal) libcontainer libraries should be fine. Only
users that are starting containers using nsenter to actually start
containers will see the error (which is precisely what we want).
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Kir Kolyshkin