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>
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>
Looking into old opened runc issues, I noticed #1663 is there without
any resolution, and wrote this simple test checking if we mangle hook's
argv[0] in any way.
Apparently we're good, but the test actually makes sense to have.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Historically, when HOME is not explicitly set in process.Env,
and UID to run as doesn't have a corresponding entry in container's
/etc/passwd, runc sets HOME=/ as a fallback.
Add the corresponding check, for the sake of backward compatibility
preservation.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is to ensure that changes in Process.Env handling won't affect
StartContainer hook.
Reported-by: lfbzhm <lifubang@acmcoder.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Assigning a multi-line value to a bash variable should not be so complex.
While at it, slightly reformat create_runtime_hook.
No functional change.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Instead of having every test helper binary in its own directory, let's
use /tests/cmd/_bin as a destination directory.
This allows for simpler setup/cleanup.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.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>
This reverts commit 65a1074c75.
We needed [1] because when we removed the bindfd logic in [2] we had not
yet moved the binary cloning logic to Go and thus it was necessary to
increase the memory limit in CI because the clone was happening after
joining the cgroup. However, [3] finally moved that code to Go and thus
the cloning is now done outside of the container's cgroup and thus is no
longer accounted as part of the container's memory usage at any point.
Now we can properly support running a simple container with lower memory
usage as we did before.
[1]: commit 65a1074c75 ("increase memory.max in cgroups.bats")
[2]: commit b999376fb2 ("nsenter: cloned_binary: remove bindfd logic entirely")
[3]: commit 0e9a3358f8 ("nsexec: migrate memfd /proc/self/exe logic to Go code")
Signed-off-by: lfbzhm <lifubang@acmcoder.com>
[cyphar: fixed commit messages]
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Commit b999376fb2 ("nsenter: cloned_binary: remove bindfd logic
entirely") removed the read-only bind-mount logic from our cloned binary
code because it wasn't really safe because a container with
CAP_SYS_ADMIN could remove the MS_RDONLY bit and get write access to
/proc/self/exe (even with user namespaces this could've been an issue
because it's not clear if the flags are locked).
However, copying a binary does seem to have a minor performance impact.
The only way to have no performance impact would be for the kernel to
block these write attempts, but barring that we could try to reduce the
overhead by coming up with a mount that cannot have it's read-only bits
cleared.
The "simplest" solution is to create a temporary overlayfs using
fsopen(2) which uses the directory where runc exists as a lowerdir,
ensuring that the container cannot access the underlying file -- and we
don't have to do any copies.
While fsopen(2) is not free because mount namespace cloning is usually
expensive (and so it seems like the difference would be marginal), some
basic performance testing seems to indicate there is a ~60% improvement
doing it this way and that it has effectively no overhead even when
compared to just using /proc/self/exe directly:
% hyperfine --warmup 50 \
> "./runc-noclone run -b bundle ctr" \
> "./runc-overlayfs run -b bundle ctr" \
> "./runc-memfd run -b bundle ctr"
Benchmark 1: ./runc-noclone run -b bundle ctr
Time (mean ± σ): 13.7 ms ± 0.9 ms [User: 6.0 ms, System: 10.9 ms]
Range (min … max): 11.3 ms … 16.1 ms 184 runs
Benchmark 2: ./runc-overlayfs run -b bundle ctr
Time (mean ± σ): 13.9 ms ± 0.9 ms [User: 6.2 ms, System: 10.8 ms]
Range (min … max): 11.8 ms … 16.0 ms 180 runs
Benchmark 3: ./runc-memfd run -b bundle ctr
Time (mean ± σ): 22.6 ms ± 1.3 ms [User: 5.7 ms, System: 20.7 ms]
Range (min … max): 19.9 ms … 26.5 ms 114 runs
Summary
./runc-noclone run -b bundle ctr ran
1.01 ± 0.09 times faster than ./runc-overlayfs run -b bundle ctr
1.65 ± 0.15 times faster than ./runc-memfd run -b bundle ctr
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
This test case is frequently hanging recently. Might be caused
by a recent kernel update from 5.14.0-427.33.1.el9_4.x86_64 to
5.14.0-427.37.1.el9_4.x86_64.
Could not reproduce locally.
Let's skip it for now.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The issue quoted is now fixed, so add some information about the fixed
kernel version, and remove links to older discussions about idmapped
mounts security.
We can actually remove all of it for now, but let's keep it. Change
the skip message to say which kernel is required.
Amends commit b460dc39.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 98fe566c removed setting inheritable capabilities from runc exec
--cap, but neglected to also remove ambient capabilities.
An ambient capability could only be set if the same inheritable
capability is set, so as a result of the above change ambient
capabilities were not set (but due to a bug in gocapability package,
those errors are never reported).
Once we start using a library with the fix [1], that bug will become
apparent. Alas, we do not have any tests for runc exec --cap, so add
one.
Yet, if some inheritable bits are already set from spec, let's set
ambient to avoid a possible regression. Add a test case for that, too.
[1]: https://github.com/kolyshkin/capability/pull/3
Fixes: 98fe566c ("runc: do not set inheritable capabilities")
Co-authored-by: lifubang <lifubang@acmcoder.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Shared pid namespace means `runc kill` (or `runc delete -f`) have to
kill all container processes, not just init. To do so, it needs a cgroup
to read the PIDs from.
If there is no cgroup, processes will be leaked, and so such
configuration is bad and should not be allowed. To keep backward
compatibility, though, let's merely warn about this for now.
Alas, the only way to know if cgroup access is available is by returning
an error from Manager.Apply. Amend fs cgroup managers to do so (systemd
doesn't need it, since v1 can't work with rootless, and cgroup v2 does
not have a special rootless case).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This aids in failed test analysis by allowing to distinguish the output
of various commands being run as part of the test case from the output
of teardown command like runc delete.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
We reintroduced this once already because it is quite easy to miss this
subtle aspect of proc mounting. The recent migration to
securejoin.MkdirAllInRoot could have also inadvertently reintroduced
this (though it didn't).
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
`signalAllProcesses()` depends on the cgroup and is expected to fail
when runc is running in rootless without an access to the cgroup.
When `RootlessCgroups` is set to `true`, runc just ignores the error
from `signalAllProcesses` and may leak some processes running.
(See the comments in PR 4395)
In the future, runc should walk the process tree to avoid such a leak.
Note that `RootlessCgroups` is a misnomer; it is set to `false` despite
the name when cgroup v2 delegation is configured.
This is expected to be renamed in a separate commit.
Fix issue 4394
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
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>
1. Rename current -> got, expected -> want.
2. check_cgroup_value: add file name to output.
3. Improve functions description.
This is mostly to simplify debugging test failures.
Example output before:
current 500000 !? 500
After:
cpu.max.burst: got 500000, want 500
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
There's too much logic here figuring out which CPUs to use. Runc is a
low level tool and is not supposed to be that "smart". What's worse,
this logic is executed on every exec, making it slower. Some of the
logic in (*setnsProcess).start is executed even if no annotation is set,
thus making ALL execs slow.
Also, this should be a property of a process, rather than annotation.
The plan is to rework this.
This reverts commit afc23e3397.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It has been pointed out that some controllers can not accept multiple
lines of output at once. In particular, io.max can only set one device
at a time.
Practically, the only multi-line resource values we can get come from
unified.* -- let's write those line by line.
Add a test case.
Reported-by: Tao Shen <shentaoskyking@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
There are cgroup v2 systems out there that do not have cgroup swap enabled,
and this test will probably fail in there.
Move it to a separate case, guarded with requires cgroups_swap.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Add "-maxdepth 2" to not dive too deep into cgroup hierarchy.
2. Add "-type f" to look for a regular file.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This test case fails when there's a single CPU. Fix this by adding
"require smp".
While at it, document the test case and add a FIXME to maybe remove
this test later.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The issue is the same as in commit 1b2adcf but for RT scheduler;
the fix is also the same.
Test case by ls-ggg.
Co-authored-by: ls-ggg <335814617@qq.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Aleksa Sarai