For a previous attempt to fix that (and added test cases), see commit
9087f2e827.
Alas, it's not always working because of cgroup directory TOCTOU.
To solve this and avoid the race, add an error _after_ the operation.
Implement it as a method that ignores the error that should be ignored.
Instead of currentStatus(), use faster runType(), since we are not
interested in Paused status here.
For Processes(), remove the pre-op check, and only use it after getting
an error, making the non-error path more straightforward.
For Signal(), add a second check after getting an error. The first check
is left as is because signalAllProcesses might print a warning if the
cgroup does not exist, and we'd like to avoid that.
This should fix an occasional failure like this one:
not ok 84 kill detached busybox
# (in test file tests/integration/kill.bats, line 27)
# `[ "$status" -eq 0 ]' failed
....
# runc kill test_busybox KILL (status=0):
# runc kill -a test_busybox 0 (status=1):
# time="2023-04-04T18:24:27Z" level=error msg="lstat /sys/fs/cgroup/devices/system.slice/runc-test_busybox.scope: no such file or directory"
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
These functions were added in ancient times, facilitating the
docker-in-docker case when cgroup namespace was not available.
As pointed out in commit 2b28b3c276, using init 1 cgroup is not
correct because it won't work in case of host PID namespace.
The last user of GetInitCgroup was removed by commit
54e20217a8. GetInitCgroupPath was never used
as far as I can see, nor was I able to find any external users.
Remove both functions. Modify the comment in libct/cg/fs.subsysPath
to not refer to GetInitCgroupPath.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Systemd v252 (available in CentOS Stream 9 in our CI) added support
for setting cpu.idle (see [1]). The way it works is:
- if CPUWeight == 0, cpu.idle is set to 1;
- if CPUWeight != 0, cpu.idle is set to 0.
This commit implements setting cpu.idle in systemd cgroup driver via a
unit property. In case CPUIdle is set to non-zero value, the driver sets
adds CPUWeight=0 property, which will result in systemd setting cpu.idle
to 1.
Unfortunately, there's no way to set cpu.idle to 0 without also changing
the CPUWeight value, so the driver doesn't do anything if CPUIdle is
explicitly set to 0. This case is handled by the fs driver which is
always used as a followup to setting systemd unit properties.
Also, handle cpu.idle set via unified map. In case it is set to non-zero
value, add CPUWeight=0 property, and ignore cpu.weight (otherwise we'll
get two different CPUWeight properties set).
Add a unit test for new values in unified map, and an integration test case.
[1] https://github.com/systemd/systemd/pull/23299
[2] https://github.com/opencontainers/runc/issues/3786
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
In code that checks that the resource name is in the for
Using strings.SplitN is an overkill in this case, resulting in
allocations and thus garbage to collect.
Using strings.IndexByte and checking that result is not less than 1
(meaning there is a period, and it is not the first character) is
sufficient here.
Fixes: 0cb8bf67a3
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit d08bc0c1b3 ("runc run: warn on non-empty cgroup") introduced
a warning when a container is started in a non-empty cgroup. Such
configuration has lots of issues.
In addition to that, such configuration is not possible at all when
using the systemd cgroup driver.
As planned, let's promote this warning to an error, and fix the test
case accordingly.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
In case a systemd unit fails (for example, timed out or OOM-killed),
systemd keeps the unit. This prevents starting a new container with
the same systemd unit name.
The fix is to call reset-failed in case UnitExists error is returned,
and retry once.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit d223e2adae ("Ignore error when starting transient unit
that already exists" modified the code handling errors from startUnit
to ignore UnitExists error.
Apparently it was done so that kubelet can create the same pod slice
over and over without hitting an error (see [1]).
While it works for a pod slice to ensure it exists, it is a gross bug
to ignore UnitExists when creating a container. In this case, the
container init PID won't be added to the systemd unit (and to the
required cgroup), and as a result the container will successfully
run in a current user cgroup, without any cgroup limits applied.
So, fix the code to only ignore UnitExists if we're not adding a process
to the systemd unit. This way, kubelet will keep working as is, but
runc will refuse to create containers which are not placed into a
requested cgroup.
[1] https://github.com/opencontainers/runc/pull/1124
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Since commit 39914db679 this function is not used by runc (see
that commit to learn why this function is not that good).
I was not able to find any external users either.
Since it's not a good function, with no users, and it is rather trivial,
let's remove it right away (rather than mark as deprecated).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The setRecAttr is only called for "bind" case, as cases end with a
return statement. Indeed, recursive mount attributes only make sense for
bind mounts.
Move the code to under case "bind" to improve readability. No change in
logic.
Fixes: 382eba4354
Reported-by: Sebastiaan van Stijn <github@gone.nl>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Sometimes, the init process is not in the root cgroup.
This can be noted by GetInitPath, which already scrubs the path of `init.scope`.
This was encountered when trying to patch the Kubelet to handle systemd being in a separate cpuset
from root (to allow load balance disabling for containers). At present, there's no way to have libcontainer or runc
manage cgroups in a hierarchy outside of the one init is in (unless the path contains `init.scope`, which is limiting)
Signed-off-by: Peter Hunt <pehunt@redhat.com>
There is some kind of a race in CentOS 7 which sometimes result in one
of these tests failing like this:
systemd_test.go:136: mkdir /sys/fs/cgroup/hugetlb/system.slice/system-runc_test_pods.slice: no such file or directory
or
systemd_test.go:187: open /sys/fs/cgroup/cpuset/system.slice/system-runc_test_pods.slice/cpuset.mems: no such file or directory
As this is only happening on CentOS 7, let's skip this test on this
platform.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 3291d66b98 introduced a check for /proc and /sys, making sure
the destination (dest) is a directory (and not e.g. a symlink).
Later, a hunk from commit 0ca91f44f switched from using filepath.Join
to SecureJoin for dest. As SecureJoin follows and resolves symlinks,
the check whether dest is a symlink no longer works.
To fix, do the check without/before using SecureJoin.
Add integration tests to make sure we won't regress.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Older kernels may return EINVAL on unshare when a process is reading
runc's /proc/$PID/status or /proc/$PID/maps. This was fixed by kernel
commit 12c641ab8270f ("unshare: Unsharing a thread does not require
unsharing a vm") in Linuxt v4.3.
For CentOS 7, the fix was backported to CentOS 7.7 (kernel 3.10.0-1062).
To work around this kernel bug, let's retry on EINVAL a few times.
Reported-by: zzyyzte <zhang.yu58@zte.com.cn>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It was found that rootless runc makes `/sys/fs/cgroup` writable in following conditons:
1. when runc is executed inside the user namespace, and the config.json does not specify the cgroup namespace to be unshared
(e.g.., `(docker|podman|nerdctl) run --cgroupns=host`, with Rootless Docker/Podman/nerdctl)
2. or, when runc is executed outside the user namespace, and `/sys` is mounted with `rbind, ro`
(e.g., `runc spec --rootless`; this condition is very rare)
A container may gain the write access to user-owned cgroup hierarchy `/sys/fs/cgroup/user.slice/...` on the host.
Other users's cgroup hierarchies are not affected.
To fix the issue, this commit does:
1. Remount `/sys/fs/cgroup` to apply `MS_RDONLY` when it is being bind-mounted
2. Mask `/sys/fs/cgroup` when the bind source is unavailable
Fix CVE-2023-25809 (GHSA-m8cg-xc2p-r3fc)
Co-authored-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
The purpose of this test is to check that there are no extra file
descriptors left open after repeated calls to runContainer. In fact,
the first call to runContainer leaves a few file descriptors opened,
and this is by design.
Previously, this test relied on two things:
1. some other tests were run before it (and thus all such opened-once
file descriptors are already opened);
2. explicitly excluding fd opened to /sys/fs/cgroup.
Now, if we run this test separately, it will fail (because of 1 above).
The same may happen if the tests are run in a random order.
To fix this, add a container run before collection the initial fd list,
so those fds that are opened once are included and won't be reported.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
stage_2_pid is not yet assigned, so this kills the PID -1, but as
the sane_kill() wrapper is just a nop in that case. Just remove these
calls to kill stage_2_pid before it is cloned/assigned.
I've checked by executing the error paths that no binary is left by mistake.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
centos-9 unit test sometimes fails with:
=== RUN TestPodSkipDevicesUpdate
systemd_test.go:114: container stderr not empty: basename: missing operand
Try 'basename --help' for more information.
--- FAIL: TestPodSkipDevicesUpdate (0.11s)
I'm not sure why the container output is an error in basename. It seems
likely that the bashrc in that distro is kind of broken. Let's just run
a sleep command and forget about bash.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
In 18c4760a (libct: fixStdioPermissions: skip chown if not needed)
the check whether the STDIO file descriptors point to /dev/null was
removed which can cause /dev/null to change ownership e.g. when using
docker exec on a running container:
$ ls -l /dev/null
crw-rw-rw- 1 root root 1, 3 Aug 1 14:12 /dev/null
$ docker exec -u test 0ad6d3064e9d ls
$ ls -l /dev/null
crw-rw-rw- 1 test root 1, 3 Aug 1 14:12 /dev/null
Signed-off-by: Jaroslav Jindrak <dzejrou@gmail.com>
First, check if strdup() fails and error out.
While we are there, the else case was missing brackets, as we only need
to check ret in the else case. Fix that too
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
configs package can no longer be built on non-Linux OS, such as Darwin.
When running `GOOS=darwin go build` on the packge, we had the following
errors:
```
./configs/mount.go:34:16: undefined: unix.MountAttr
./configs/mount.go:47:22: undefined: unix.MS_BIND
```
Let's ensure that the linux specific bits are handled in mount_linux.go,
and introduce a _unsupported file, similar to how cgroups file is
handled within the package. This'll facilitate utilization of the pkg
for other projects that care about Darwin.
Signed-off-by: Eric Ernst <eric_ernst@apple.com>
Rewrite systemdVersionAtoi to not use regexp, and fix two issues:
1. It was returning 0 (rather than -1) for some errors.
2. The comment was saying that the input string is without quotes,
while in fact it is.
Note the new function, similar to the old one, works on input either
with or without quotes. Amend the test to add test cases without quotes.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Kir Kolyshkin