The source of the bind mount might not be accessible in a different user
namespace because a component of the source path might not be traversed
under the users and groups mapped inside the user namespace. This caused
errors such as the following:
# time="2020-06-22T13:48:26Z" level=error msg="container_linux.go:367:
starting container process caused: process_linux.go:459:
container init caused: rootfs_linux.go:58:
mounting \"/tmp/busyboxtest/source-inaccessible/dir\"
to rootfs at \"/tmp/inaccessible\" caused:
stat /tmp/busyboxtest/source-inaccessible/dir: permission denied"
To solve this problem, this patch performs the following:
1. in nsexec.c, it opens the source path in the host userns (so we have
the right permissions to open it) but in the container mntns (so the
kernel cross mntns mount check let us mount it later:
https://github.com/torvalds/linux/blob/v5.8/fs/namespace.c#L2312).
2. in nsexec.c, it passes the file descriptors of the source to the
child process with SCM_RIGHTS.
3. In runc-init in Golang, it finishes the mounts while inside the
userns even without access to the some components of the source
paths.
Passing the fds with SCM_RIGHTS is necessary because once the child
process is in the container mntns, it is already in the container userns
so it cannot temporarily join the host mntns.
This patch uses the existing mechanism with _LIBCONTAINER_* environment
variables to pass the file descriptors from runc to runc init.
This patch uses the existing mechanism with the Netlink-style bootstrap
to pass information about the list of source mounts to nsexec.c.
Rootless containers don't use this bind mount sources fdpassing
mechanism because we can't setns() to the target mntns in a rootless
container (we don't have the privileges when we are in the host userns).
This patch takes care of using O_CLOEXEC on mount fds, and close them
early.
Fixes: #2484.
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
Export getIntelRdtRoot function as Root.
This is needed by google/cadvisor, which is (ab)using GetIntelRdtPath,
removed by commit 7296dc1712.
While at it, do some minimal refactoring to always use Root()
internally, not relying on variable value. Other than that it's just
some renaming.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
If the container binary to be run is removed in between runc create
and runc start, the latter spits the following error:
> can't exec user process: no such file or directory
This is a bit confusing since we don't see what file is missing.
Wrap the unix.Exec error into os.PathError, like in many other cases,
to provide some context. Remove the error wrapping from
(*linuxStandardInit).Init as it is now redundant.
With this patch, the error is now:
> exec /bin/false: no such file or directory
Reported-by: Daniel J Walsh <dwalsh@redhat.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
In case hugetlb is not supported, GetStats() should not error out,
and yet it does.
Assume that if GetHugePageSize return an error, hugetlb is
not supported (this is what cgroup v1 manager do).
Fixes: 89a87adb
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Currently, we can create subcgroup in a rootless container with systemd cgroupv2 on centos8.
But after the container exited, the container cgroup and its subcgroup will not be removed.
Fix this by removing all directories recursively.
Fixes: https://github.com/opencontainers/runc/issues/3225
Signed-off-by: Kang Chen <kongchen28@gmail.com>
In some setups, multiple cgroups are used inside a container,
and sometime there is a need to execute a process in a particular
sub-cgroup (in case of cgroup v1, for a particular controller).
This is what this commit implements.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Currently the parent process of the container is moved to the right
cgroup v2 tree when systemd is using a hybrid model (last line with 0::):
$ runc --systemd-cgroup run myid
/ # cat /proc/self/cgroup
12:cpuset:/system.slice/runc-myid.scope
11:blkio:/system.slice/runc-myid.scope
10:devices:/system.slice/runc-myid.scope
9:hugetlb:/system.slice/runc-myid.scope
8:memory:/system.slice/runc-myid.scope
7:rdma:/
6:perf_event:/system.slice/runc-myid.scope
5:net_cls,net_prio:/system.slice/runc-myid.scope
4:freezer:/system.slice/runc-myid.scope
3:pids:/system.slice/runc-myid.scope
2:cpu,cpuacct:/system.slice/runc-myid.scope
1:name=systemd:/system.slice/runc-myid.scope
0::/system.slice/runc-myid.scope
However, if a second process is executed in the same container, it is
not moved to the right cgroup v2 tree:
$ runc exec myid /bin/sh -c 'cat /proc/self/cgroup'
12:cpuset:/system.slice/runc-myid.scope
11:blkio:/system.slice/runc-myid.scope
10:devices:/system.slice/runc-myid.scope
9:hugetlb:/system.slice/runc-myid.scope
8:memory:/system.slice/runc-myid.scope
7:rdma:/
6:perf_event:/system.slice/runc-myid.scope
5:net_cls,net_prio:/system.slice/runc-myid.scope
4:freezer:/system.slice/runc-myid.scope
3:pids:/system.slice/runc-myid.scope
2:cpu,cpuacct:/system.slice/runc-myid.scope
1:name=systemd:/system.slice/runc-myid.scope
0::/user.slice/user-1000.slice/session-8.scope
This commit makes that processes executed with exec are placed into the
right cgroup v2 tree. The implementation checks if systemd is using a
hybrid mode (by checking if cgroups v2 is mounted in
/sys/fs/cgroup/unified), if yes, the path of the cgroup v2 slice for
this container is saved into the cgroup path list.
The fs group driver has a similar issue, in this case none of the runc
run or runc exec commands put the process in the right cgroups v2. This
commit also fixes that.
Having the processes of the container in its own cgroup v2 is useful
for any BPF programs that rely on bpf_get_current_cgroup_id(), like
https://github.com/kinvolk/inspektor-gadget/ for instance.
[@kolyshkin: rebased]
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The function used here, cgroups.EnterPid, silently skips non-existing
paths, and it does not look like a good idea to do so for an existing
container with already configured cgroups.
Switch to cgroups.WriteCgroupProc which does not do that, so in case
a cgroup does not exist, we'll get an error.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
No need to add a file name to the error messages, as errors from
OpenFile and (*os.File).Write both contain the file name already.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It is assumed that m.config is not nil, so these checks are redundant
(in case it is nil, NewManager panics and this code is unreachable).
Note that cgroups/manager.New checks that config is not nil.
Remove them.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Cgroup controllers should never panic, and yet sometimes they do.
Add a unit test to check that controllers never panic when called with
nil arguments and/or resources, and fix a few found cases.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
cgName and cgParent are only used when cgPath is empty, so move
their cleaning to the body of the appropriate "if" statement.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This way we
- won't re-initialize the paths if they were provided;
- will always have paths ready for every method.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is already documented but I guess more explanations (in particular,
why the path is being removed from paths) won't hurt.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Separate path initialization logic from Apply to initPaths,
and call initPaths from NewManager, so:
- we can error out early (in NewManager rather than Apply);
- always have m.paths available (e.g. in Destroy or Exists).
- do not unnecessarily call subsysPath from Apply in case
the paths were already provided.
2. Add a check for non-nil cgroups.Resources to NewManager,
since initPaths, as well as some controller's Apply methods,
need it.
3. Move cgroups.Resources.Unified check from Apply to NewManager,
so we can error out early (same check exists in Set).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Make Rootless and Systemd flags part of config.Cgroups.
2. Make all cgroup managers (not just fs2) return error (so it can do
more initialization -- added by the following commits).
3. Replace complicated cgroup manager instantiation in factory_linux
by a single (and simple) libcontainer/cgroups/manager.New() function.
4. getUnifiedPath is simplified to check that only a single path is
supplied (rather than checking that other paths, if supplied,
are the same).
[v2: can't -> cannot]
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Wire through CRIU's support to change the mount context on restore.
This is especially useful if restoring a container in a different pod.
Single container restore uses the same SELinux process label and
same mount context as during checkpointing. If a container is being
restored into an existing pod the process label and the mount context
needs to be changed to the context of the pod.
Changing process label on restore is already supported by runc. This
patch adds the possibility to change the mount context.
Signed-off-by: Adrian Reber <areber@redhat.com>
runc delete -f is not working for a paused container, since in cgroup v1
SIGKILL does nothing if a process is frozen (unlike cgroup v2, in which
you can kill a frozen process with a fatal signal).
Theoretically, we only need this for v1, but doing it for v2 as well is
OK.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Dismantle and remove struct cgroupData. It contained three unrelated
entities (cgroup paths, pid, and resources), and made the code
harder to read. Most importantly, though, it is not needed.
Now, subsystems' Apply methods take path, resources, and pid.
To a reviewer -- the core of the changes is in fs.go and paths.go,
the rest of it is adapting to the new signatures and related test
changes.
2. Dismantle and remove struct cgroupTestUtil. This is a followup
to the previous item -- since cgroupData is gone, there is nothing
to hold in cgroupTestUtil. The change itself is very small (see
util_test.go), but this patch is big because of it -- mostly
because we had to replace helper.cgroup.Resources with
&config.Resources{}.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
In case c.Path is set, c.Name and c.Parent are not used, and so
calls to utils.CleanPath are entirely unnecessary. Move them to
inside of the "if" statement body.
Get rid of the intermediate cgPath variable, it is not needed.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Now fs.go is not very readable as its public API functions are
intermixed with internal stuff about getting cgroup paths.
Move that out to paths.go, without changing any code.
Same for the tests -- move paths-related tests to paths_test.go.
This commit is separate to make the review easier.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
As ExpandSlice("system.slice") returns "/system.slice", there is no need
to call it for such paths (and the slash will be added by path.Join
anyway).
The same optimization was already done for v2 as part of commit
bf15cc99b1.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
We were checking if a unit is a slice two times. Consolidate those
checks, and improve comments while we're at it.
The code is the same in v1 and v2 but it's too complicated to factor it
out, thus we just do the same changes in v1.go and v2.go.
No functional change.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Currently, if the log level is not set to e.g. "debug", runc init sends
some debug logs to the parent, which parses and discards it.
It is better to not send those in the first place.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The code already parses an environment variable into an integer twice,
and we're about to add a third one.
Factor it out to getenv_int().
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This makes it possible to use bail() even if logging is not set up
(yet), so we don't have to think whether it's OK to use it or not.
In addition, this might help some unit tests that do not set log
forwarding.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Two new seccomp actions have been added to the libseccomp-golang
dependency, which can be now supported by runc, too.
ActKillThread kills the thread that violated the rule. It is the same as
ActKill. All other threads from the same thread group will continue to
execute.
ActKillProcess kills the process that violated the rule. All threads in
the thread group are also terminated. This action is only usable when
libseccomp API level 3 or higher is supported.
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
These are just boilerplate and are only really useful for the two
actions which require us to set a default errno/aux value (ActErrno and
ActTrace).
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Kir Kolyshkin (6):
runc --debug: shorter caller info
libct/logs: do not show caller in nsexec logs
libct/logs: parse log level implicitly
libct/logs: test: make more robust
libct/logs: remove ConfigureLogging
init.go, main.go: don't use logs.ConfigureLogging
LGTMs: thaJeztah cyphar
Kir Kolyshkin (3):
libct/system: add I and P process states
libct/system.Stat: fix/improve/speedup
libct/system/proc_test: fix, improve, add benchmark
LGTMs: thaJeztah cyphar
Extend the SetupSeccomp tests by adding the following cases:
- Test nil config
- Test empty config
- Test bad action and architecture
- Test all possible actions
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
This commit implements support for the SCMP_ACT_NOTIFY action. It
requires libseccomp-2.5.0 to work but runc still works with older
libseccomp if the seccomp policy does not use the SCMP_ACT_NOTIFY
action.
A new synchronization step between runc[INIT] and runc run is introduced
to pass the seccomp fd. runc run fetches the seccomp fd with pidfd_get
from the runc[INIT] process and sends it to the seccomp agent using
SCM_RIGHTS.
As suggested by @kolyshkin, we also make writeSync() a wrapper of
writeSyncWithFd() and wrap the error there. To avoid pointless errors,
we made some existing code paths just return the error instead of
re-wrapping it. If we don't do it, error will look like:
writing syncT <act>: writing syncT: <err>
By adjusting the code path, now they just look like this
writing syncT <act>: <err>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
SendFds is a helper function for sending a set of file descriptors and a message
over a unix domain socket.
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
if function returns error before WriteJSON defer, error will not be
printed out, so move this defer as early as possible and use logrus to
print out error if returns before it.
Signed-off-by: xiadanni <xiadanni1@huawei.com>
Commit 9f3d7534ea enabled logrus to show information about log
caller, if --debug is set. It is helpful in many scenarios, but does
not work very well when we are debugging runc init, for example:
# runc --debug run -d xx4557
DEBU[0000]libcontainer/logs/logs.go:45 github.com/opencontainers/runc/libcontainer/logs.processEntry() nsexec[279687]: logging set up
DEBU[0000]libcontainer/logs/logs.go:45 github.com/opencontainers/runc/libcontainer/logs.processEntry() nsexec[279687]: logging set up
DEBU[0000]libcontainer/logs/logs.go:45 github.com/opencontainers/runc/libcontainer/logs.processEntry() nsexec[279687]: => nsexec container setup
DEBU[0000]libcontainer/logs/logs.go:45 github.com/opencontainers/runc/libcontainer/logs.processEntry() nsexec[279687]: update /proc/self/oom_score_adj to '30'
As we're merely forwarding the logs here, printing out filename:line and
function is useless and clutters the logs a log.
To fix, create and use a copy of the standard logger with caller info
turned off.
With this in place, nsexec logs are sane again:
# runc --debug --log-format=text run -d xe34
DEBU[0000] nsexec[293595]: logging set up
DEBU[0000] nsexec[293595]: logging set up
DEBU[0000] nsexec[293595]: => nsexec container setup
DEBU[0000] nsexec[293595]: update /proc/self/oom_score_adj to '30'
This patch also changes Logf to Log in processEntry, as this is what it
should be.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Alban Crequy