My first attempt to simplify this and make it less costly focussed on
the way constructors are called. I was under the impression that the ELF
specification mandated that arg, argv, and actually even envp need to be
passed to functions located in the .init_arry section (aka
"constructors"). Actually, the specifications is (cf. [2]):
SHT_INIT_ARRAY
This section contains an array of pointers to initialization functions,
as described in ``Initialization and Termination Functions'' in Chapter
5. Each pointer in the array is taken as a parameterless procedure with
a void return.
which means that this becomes a libc specific decision. Glibc passes
down those args, musl doesn't. So this approach can't work. However, we
can at least remove the environment parsing part based on POSIX since
[1] mandates that there should be an environ variable defined in
unistd.h which provides access to the environment. See also the relevant
Open Group specification [1].
[1]: http://pubs.opengroup.org/onlinepubs/9699919799/
[2]: http://www.sco.com/developers/gabi/latest/ch4.sheader.html#init_array
Fixes: CVE-2019-5736
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The detection for scope properties (whether scope units support
DefaultDependencies= or Delegate=) has always been broken, since systemd
refuses to create scopes unless at least one PID is attached to it (and
this has been so since scope units were introduced in systemd v205.)
This can be seen in journal logs whenever a container is started with
libpod:
Feb 11 15:08:07 myhost systemd[1]: libcontainer-12345-systemd-test-default-dependencies.scope: Scope has no PIDs. Refusing.
Feb 11 15:08:07 myhost systemd[1]: libcontainer-12345-systemd-test-default-dependencies.scope: Scope has no PIDs. Refusing.
Since this logic never worked, just assume both attributes are supported
(which is what the code does when detection fails for this reason, since
it's looking for an "unknown attribute" or "read-only attribute" to mark
them as false) and skip the detection altogether.
Signed-off-by: Filipe Brandenburger <filbranden@google.com>
There are quite a few circumstances where /proc/self/exe pointing to a
pretty important container binary is a _bad_ thing, so to avoid this we
have to make a copy (preferably doing self-clean-up and not being
writeable).
We require memfd_create(2) -- though there is an O_TMPFILE fallback --
but we can always extend this to use a scratch MNT_DETACH overlayfs or
tmpfs. The main downside to this approach is no page-cache sharing for
the runc binary (which overlayfs would give us) but this is far less
complicated.
This is only done during nsenter so that it happens transparently to the
Go code, and any libcontainer users benefit from it. This also makes
ExtraFiles and --preserve-fds handling trivial (because we don't need to
worry about it).
Fixes: CVE-2019-5736
Co-developed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
For some reason, libcontainer/integration has a whole bunch of incorrect
usages of libcontainer.Factory -- causing test failures with a set of
security patches that will be published soon. Fixing ths is fairly
trivial (switch to creating a new libcontainer.Factory once in each
process, rather than creating one in TestMain globally).
Signed-off-by: Aleksa Sarai <asarai@suse.de>
When creating a new user namespace, the kernel doesn't allow to mount
a new procfs or sysfs file system if there is not already one instance
fully visible in the current mount namespace.
When using --no-pivot we were effectively inhibiting this protection
from the kernel, as /proc and /sys from the host are still present in
the container mount namespace.
A container without full access to /proc could then create a new user
namespace, and from there able to mount a fully visible /proc, bypassing
the limitations in the container.
A simple reproducer for this issue is:
unshare -mrfp sh -c "mount -t proc none /proc && echo c > /proc/sysrq-trigger"
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
since commit df3fa115f9 it is not
possible to set a kernel memory limit when using the systemd cgroups
backend as we use cgroup.Apply twice.
Skip enabling kernel memory if there are already tasks in the cgroup.
Without this patch, runc fails with:
container_linux.go:344: starting container process caused
"process_linux.go:311: applying cgroup configuration for process
caused \"failed to set memory.kmem.limit_in_bytes, because either
tasks have already joined this cgroup or it has children\""
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
This patch fixes a corner case when destroy a container:
If we start a container without 'intelRdt' config set, and then we run
“runc update --l3-cache-schema/--mem-bw-schema” to add 'intelRdt' config
implicitly.
Now if we enter "exit" from the container inside, we will pass through
linuxContainer.Destroy() -> state.destroy() -> intelRdtManager.Destroy().
But in IntelRdtManager.Destroy(), IntelRdtManager.Path is still null
string, it hasn’t been initialized yet. As a result, the created rdt
group directory during "runc update" will not be removed as expected.
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
For the newly integrated feature to use CRIU configuration files the
test is broken without an additional CRIU patch.
The test changes CRIU's log file. Changing the log file is unfortunately
the only thing which is in broken in CRIU 3.11. But it is the easiest
option for testing. With CRIU 3.12 this will be fixed. All other CRIU
options can be changed with a CRIU configuration file.
With this change the CRIU 3.11 feature can be merged into runc with a
test and for the user it should just work, if they are not trying to
change CRIU's log file.
Signed-off-by: Adrian Reber <areber@redhat.com>
CRIU 3.11 introduces configuration files:
https://criu.org/Configuration_fileshttps://lisas.de/~adrian/posts/2018-Nov-08-criu-configuration-files.html
This enables the user to influence CRIU's behaviour without code changes
if using new CRIU features or if the user wants to enable certain CRIU
behaviour without always specifying certain options.
With this it is possible to write 'tcp-established' to the configuration
file:
$ echo tcp-established > /etc/criu/runc.conf
and from now on all checkpoints will preserve the state of established
TCP connections. This removes the need to always use
$ runc checkpoint --tcp-stablished
If the goal is to always checkpoint with '--tcp-established'
It also adds the possibility for unexpected CRIU behaviour if the user
created a configuration file at some point in time and forgets about it.
As a result of the discussion in https://github.com/opencontainers/runc/pull/1933
it is now also possible to define a CRIU configuration file for each
container with the annotation 'org.criu.config'.
If 'org.criu.config' does not exist, runc will tell CRIU to use
'/etc/criu/runc.conf' if it exists.
If 'org.criu.config' is set to an empty string (''), runc will tell CRIU
to not use any runc specific configuration file at all.
If 'org.criu.config' is set to a non-empty string, runc will use that
value as an additional configuration file for CRIU.
With the annotation the user can decide to use the default configuration
file ('/etc/criu/runc.conf'), none or a container specific configuration
file.
Signed-off-by: Adrian Reber <areber@redhat.com>
The kernel will sometimes return EINVAL when writing a pid to a
cgroup.procs file. It does so when the task being added still has the
state TASK_NEW.
See: https://elixir.bootlin.com/linux/v4.8/source/kernel/sched/core.c#L8286
Co-authored-by: Danail Branekov <danailster@gmail.com>
Signed-off-by: Tom Godkin <tgodkin@pivotal.io>
Signed-off-by: Danail Branekov <danailster@gmail.com>
when restore container from a checkpoint directory, we should get
pid from criu notify, since c.initProcess has not been created.
Signed-off-by: Ace-Tang <aceapril@126.com>
When built with nokmem we explicitly are disabling support for kmemcg,
but it is a strict specification requirement that if we cannot fulfil an
aspect of the container configuration that we error out.
Completely ignoring explicitly-requested kmemcg limits with nokmem would
undoubtably lead to problems.
Fixes: 6a2c155968 ("libcontainer: ability to compile without kmem")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
After discussion with Victor, he mentioned that he wanted to rescind
his maintainership a few years ago (due to a change in priorities and
what he's been working on) but wasn't sure what the right process is.
Thanks for your hard work Victor!
Signed-off-by: Aleksa Sarai <asarai@suse.de>
After talking to Rohit, he mentioned that he wasn't aware he was still a
maintainer (and that his maintainership was grandfathered from his
Docker maintainership). He's moved on to other projects now, and thus
said he would happily step down as maintainer. (Since he's stepping down
voluntarily, this doesn't require a mailing-list vote.)
Thanks for all of your hard work, Rohit!
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Aleksa Sarai
Christian Brauner
Mrunal Patel
Daniel, Dao Quang Minh
Filipe Brandenburger
John Howard
Michael Crosby
Adrian Reber
Giuseppe Scrivano
Xiaochen Shen
JoeWrightss
Tom Godkin
Ace-Tang
Kenta Tada
Lifubang