Those are no longer needed with shellcheck v0.10.0 (possibly with an
earlier version, too, but I am too lazy to check that).
While at it, fix a typo in the comment.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
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>
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>
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>
Now that runc-dmz is opt-in, we no longer need to try to detect whether
SELinux would cause issues for us. We can also remove the
special-purpose build-tag we added.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
If it is compiled, the user needs to opt-in with this env variable to
use it.
While we are there, remove the RUNC_DMZ=legacy as that is now the
default.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>
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>
Given we've had several bugs in this behaviour that have now been fixed,
add an integration test that makes sure that you can start a container
that joins all of the namespaces of a second container.
The only namespace we do not join is the mount namespace, because
joining a namespace that has been pivot_root'd leads to a bunch of
errors. In principle, removing everything from config.json that requires
a mount _should_ work, but the root.path configuration is mandatory and
we cannot just ignore setting up the rootfs in the namespace joining
scenario (if the user has configured a different rootfs, we need to use
it or error out, and there's no reasonable way of checking if if the
rootfs paths are the same that doesn't result in spaghetti logic).
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Apparently, sometimes a short-lived "runc run" produces result with \r
and sometimes without. As a result, we have an occasional failure of
"runc run with tmpfs perms" test.
The solution (to the flaky test) is to use the first line of the output
(like many other tests do).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
When a directory already exists (or after a container is restarted) the
perms of the directory being mounted to were being used even when a
different permission is set on the tmpfs mount options.
This prepends the original directory perms to the mount options.
If the perms were already set in the mount opts then those perms will
win.
This eliminates the need to perform a chmod after mount entirely.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Currently only amd64 and arm64v8 tarball have been checked in testdata,
while busybox bundle is downloaded on fly, and supports multiple architectures.
To enable integration tests for more architectures, the hello world
bundle is replaced by busybox one.
Signed-off-by: Shengjing Zhu <zhsj@debian.org>
The variable $ROOTLESS, as set by helpers.bash and used in many places,
provides the same value as $EUID which is always set by bash. Since we
are using bash, we can rely on $EUID being omnipresent.
Modify all uses accordingly, and since the value is known to be a
number, omit the quoting.
Similarly, replace all uses of $(id -u) to $EUID.
Do some trivial cleanups along the way, such as
- simplify some if A; then B; to A && B;
- do not use [[ instead of [ where not necessary.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
lifubang