The "dmz" name was originally used because the libcontainer/dmz package
housed the runc-dmz binary, but since we removed it in commit
871057d863 ("drop runc-dmz solution according to overlay solution")
the name is an anachronism and we should just give it a more
self-explanatory name.
So, call it libcontainer/exeseal because the purpose of the package is
to provide tools to seal /proc/self/exe against attackers.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Arguably these docs should live elsewhere (especially if we plan to
remove memfd-bind in the future), but for now this is the only place
that fully explains this issue.
Suggested-by: Rodrigo Campos <rodrigoca@microsoft.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Because we have the overlay solution, we can drop runc-dmz binary
solution since it has too many limitations.
Signed-off-by: lifubang <lifubang@acmcoder.com>
Let's point to the relevant README directly in the systemd unit file,
as it is hard to find in the whole nine yards of the runc repo.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The example of starting memfd-bind via systemd in README did not work
for me (Fedora 40, systemd 255):
# systemctl status memfd-bind@/usr/bin/runc
Invalid unit name "memfd-bind@/usr/bin/runc" escaped as "memfd-bind@-usr-bin-runc" (maybe you should use systemd-escape?).
○ memfd-bind@-usr-bin-runc.service
Loaded: bad-setting (Reason: Unit memfd-bind@-usr-bin-runc.service has a bad unit file setting.)
Active: inactive (dead)
Docs: https://github.com/opencontainers/runc
So, let's use systemd-escape -p ("path") in the README example,
and use %f in the systemd unit file to prepend the slash to the
filename.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The following commands are moved from `contrib/cmd` to `tests/cmd`:
- fs-idmap
- pidfd-kill
- recvtty
- remap-rootfs
- sd-helper
- seccompagent
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Previously, all of our userns tests worked around the remapping issue by
creating the paths that runc would attempt to create (like /proc).
However, this isn't really accurate to how real userns containers are
created, so it's much better to actually remap the rootfs.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
The container manager like containerd-shim can't use cgroup.kill feature or
freeze all the processes in cgroup to terminate the exec init process.
It's unsafe to call kill(2) since the pid can be recycled. It's good to
provide the pidfd of init process through the pidfd-socket. It's similar to
the console-socket. With the pidfd, the container manager like containerd-shim
can send the signal to target process safely.
And for the standard init process, we can have polling support to get
exit event instead of blocking on wait4.
Signed-off-by: Wei Fu <fuweid89@gmail.com>
This really isn't ideal but it can be used to avoid the largest issues
with the memfd-based runc binary protection. There are several caveats
with using this tool, see the help page for the new binary for details.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This includes quite a few cleanups and improvements to the way we do
synchronisation. The core behaviour is unchanged, but switching to
embedding json.RawMessage into the synchronisation structure will allow
us to do more complicated synchronisation operations in future patches.
The file descriptor passing through the synchronisation system feature
will be used as part of the idmapped-mount and bind-mount-source
features when switching that code to use the new mount API outside of
nsexec.c.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
We can't call log.Fatalf() and defer functions, as the former doesn't
call any defers. Let's just move the code to a new function and call
os.Exit() only in main, when all defer executed.
Now that all the code is one function, we only print twice to stderr. It
is simpler to just print to stderr instead of logging and having also
the timestamp we don't really want.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
Let's just rely on the lookup performed to find the sleep binary.
This didn't cause any issues as far as I know, I just saw this while
doing other cleanups.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
We don't really need to check if AT_RECURSIVE is possible here. We just
want to check if we can idmap the src, it doesn't matter other nested
mounts.
While we are there, allow relative paths too.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
This is what we should do, although in practice this probably won't be a
big issue as the parent also exits.
While we are there, instead of waiting for the child to finish, kill it
if we did everything we wanted to do.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.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>
This commit adds the config.json as generated by the script. Note that
the diff is minimal if you see this commit with "git show -w". The
differences are mostly whitespaces and some ordering.
We add a simple test that runs this and expects sucess.
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Implement sample seccomp agent. It's also used in integration tests in
the following commit.
Instructions how to use it in contrib/cmd/seccompagent/README.md
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Rodrigo Campos <rodrigo@kinvolk.io>
Co-authored-by: Rodrigo Campos <rodrigo@kinvolk.io>
Add a test case for an issue fixed by the previous commit.
Unfortunately, this is somewhat complicated as there's no easy way to
create a transient unit, so a binary, sd-helper, had to be added. On top
of that, an ability to create a parent/pod cgroup is added to
helpers.bash, which might be useful for future integration tests.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Using fmt.Errorf for errors that do not have %-style formatting
directives is an overkill. Switch to errors.New.
Found by
git grep fmt.Errorf | grep -v ^vendor | grep -v '%'
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
gofumpt (mvdan.cc/gofumpt) is a fork of gofmt with stricter rules.
Brought to you by
git ls-files \*.go | grep -v ^vendor/ | xargs gofumpt -s -w
Looking at the diff, all these changes make sense.
Also, replace gofmt with gofumpt in golangci.yml.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This reverts most of commit 24c05b7, as otherwise it causes
a few regressions (docker cli, TestDockerSwarmSuite/TestServiceLogsTTY).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The TestExecInTTY test case is sometimes failing like this:
> execin_test.go:332: unexpected carriage-return in output "PID USER TIME COMMAND\r\n 1 root 0:00 cat\r\n 7 root 0:00 ps\r\n"
or this:
> execin_test.go:332: unexpected carriage-return in output "PID USER TIME COMMAND\r\n 1 root 0:00 cat\n 7 root 0:00 ps\n"
(this is easy to repro with `go test -run TestExecInTTY -count 1000`).
This is caused by a race between
- an Init() (in this case it is is (*linuxSetnsInit.Init(), but
(*linuxStandardInit).Init() is no different in this regard),
which creates a pty pair, sends pty master to runc, and execs
the container process,
and
- a parent runc process, which receives the pty master fd and calls
ClearONLCR() on it.
One way of fixing it would be to add a synchronization mechanism
between these two, so Init() won't exec the process until the parent
sets the flag. This seems excessive, though, as we can just move
the ClearONLCR() call to Init(), putting it right after console.NewPty().
Note that bug only happens in the TestExecInTTY test case, but
from looking at the code it seems like it can happen in runc run
or runc exec, too.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Fixes the following errcheck linter warnings
> contrib/cmd/recvtty/recvtty.go:115:10: Error return value of `io.Copy` is not checked (errcheck)
> io.Copy(os.Stdout, c)
> ^
> contrib/cmd/recvtty/recvtty.go:120:11: Error return value of `io.Copy` is not checked (errcheck)
> io.Copy(c, os.Stdin)
> ^
> contrib/cmd/recvtty/recvtty.go:175:11: Error return value of `io.Copy` is not checked (errcheck)
> io.Copy(devnull, master)
> ^
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It looks like we need to wait for the both copy goroutines to finish,
not just the one that happen to finish first.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is mostly just useful for testing with the "single" mode, since it
allows you to run recvtty in the background without the console being
closed.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
This moves all console code to use github.com/containerd/console library to
handle console I/O. Also move to use EpollConsole by default when user requests
a terminal so we can still cope when the other side temporarily goes away.
Signed-off-by: Daniel Dao <dqminh89@gmail.com>
And use it only in local tooling that is forwarding the pseudoterminal
master. That way runC no longer has an opinion on the onlcr setting
for folks who are creating a terminal and detaching. They'll use
--console-socket and can setup the pseudoterminal however they like
without runC having an opinion. With this commit, the only cases
where runC still has applies SaneTerminal is when *it* is the process
consuming the master descriptor.
Signed-off-by: W. Trevor King <wking@tremily.us>
This maybe a nice extra but it adds complication to the usecase. The
contract is listen on the socket and you get an fd to the pty master and
that is that.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This is a proof-of-concept for the --console-socket API. It just acts as
a dumb input-output copy process (nowhere near as good as the internal
runC one since it doesn't handle console resizes or signals). It also
provides a test-friendly mode that will be used in the bats integration
tests.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Aleksa Sarai