If no seccomps flags are set in OCI runtime spec (not even the empty
set), set SPEC_ALLOW as the default (if it's supported).
Otherwise, use the flags as they are set (that includes no flags for
empty seccomp.Flags array).
This mimics the crun behavior, and makes runc seccomp performance on par
with crun.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Amend runc features to print seccomp flags. Two set of flags are added:
* known flags are those that this version of runc is aware of;
* supported flags are those that can be set; normally, this is the same
set as known flags, but due to older version of kernel and/or
libseccomp, some known flags might be unsupported.
This commit also consolidates three different switch statements dealing
with flags into one, in func setFlag. A note is added to this function
telling what else to look for when adding new flags.
Unfortunately, it also adds a list of known flags, that should be
kept in sync with the switch statement.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is aimed at solving the problem of cgroup v2 memory controller
behavior which is not compatible with that of cgroup v1.
In cgroup v1, if the new memory limit being set is lower than the
current usage, setting the new limit fails.
In cgroup v2, same operation succeeds, and the container is OOM killed.
Introduce a new setting, memory.checkBeforeUpdate, and use it to mimic
cgroup v1 behavior.
Note that this is not 100% reliable because of TOCTOU, but this is the
best we can do.
Add some test cases.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Since Go 1.19, godoc recognizes lists, code blocks, headings etc. It
also reformats the sources making it more apparent that these features
are used.
Fix a few places where it misinterpreted the formatting (such as
indented vs unindented), and format the result using the gofumpt
from HEAD, which already incorporates gofmt 1.19 changes.
Some more fixes (and enhancements) might be required.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Do not set inheritable capabilities in runc spec, runc exec --cap,
and in libcontainer integration tests.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Looking through git blame, this was added by commit 9fac18329
aka "Initial commit of runc binary", most probably by mistake.
Obviously, a container should not have access to tun/tap device, unless
it is explicitly specified in configuration.
Now, removing this might create a compatibility issue, but I see no
other choice.
Aside from the obvious misconfiguration, this should also fix the
annoying
> Apr 26 03:46:56 foo.bar systemd[1]: Couldn't stat device /dev/char/10:200: No such file or directory
messages from systemd on every container start, when runc uses systemd
cgroup driver, and the system runs an old (< v240) version of systemd
(the message was presumably eliminated by [1]).
[1] https://github.com/systemd/systemd/pull/10996/commits/d5aecba6e0b7c73657c4cf544ce57289115098e7
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
We only have one implementation of config validator, which is always
used. It makes no sense to have Validator interface.
Having validate.Validator field in Factory does not make sense for all
the same reasons.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 029b73c1b replaced a regular expression with code checking the
characters. Despite what the comment said about ASCII, the check was
performed rune by rune, not byte by byte.
Note the check was still correct, basically comparing int32's, but the
byte by byte way is a tad faster and more straightforward. The change
also fixes the issue of a misleading comment.
Benchmark before/after shows a modest improvement:
name old time/op new time/op delta
CheckPropertyName-4 164ns ± 2% 123ns ± 2% -24.73% (p=0.029 n=4+4)
name old alloc/op new alloc/op delta
CheckPropertyName-4 96.0B ± 0% 64.0B ± 0% -33.33% (p=0.029 n=4+4)
name old allocs/op new allocs/op delta
CheckPropertyName-4 6.00 ± 0% 4.00 ± 0% -33.33% (p=0.029 n=4+4)
Fixes: 029b73c1b
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 643f8a2b40 renamed isValidName to checkPropertyName, but fell
short of renaming its test and benchmark. Fix that.
Fixes: 643f8a2b40
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The new mount option "rro" makes the mount point recursively read-only,
by calling `mount_setattr(2)` with `MOUNT_ATTR_RDONLY` and `AT_RECURSIVE`.
https://man7.org/linux/man-pages/man2/mount_setattr.2.html
Requires kernel >= 5.12.
The "rro" option string conforms to the proposal in util-linux/util-linux Issue 1501.
Fix issue 2823
Similary, this commit also adds the following mount options:
- rrw
- r[no]{suid,dev,exec,relatime,atime,strictatime,diratime,symfollow}
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Delegating cgroups to the container enables more complex workloads,
including systemd-based workloads. The OCI runtime-spec was
recently updated to explicitly admit such delegation, through
specification of cgroup ownership semantics:
https://github.com/opencontainers/runtime-spec/pull/1123
Pursuant to the updated OCI runtime-spec, change the ownership of
the container's cgroup directory and particular files therein, when
using cgroups v2 and when the cgroupfs is to be mounted read/write.
As a result of this change, systemd workloads can run in isolated
user namespaces on OpenShift when the sandbox's cgroupfs is mounted
read/write.
It might be possible to implement this feature in other cgroup
managers, but that work is deferred.
Signed-off-by: Fraser Tweedale <ftweedal@redhat.com>
Using null bytes as control characters for sending strings via netlink
opens us up to a user explicitly putting a null byte in a mount string
(which JSON will happily let you do) and then causing us to open a mount
path different to the one expected.
In practice this is more of an issue in an environment such as
Kubernetes where you may have path-based access control policies (which
are more susceptible to these kinds of flaws).
Found by Google Project Zero.
Fixes: 9c444070ec ("Open bind mount sources from the host userns")
Reported-by: Felix Wilhelm <fwilhelm@google.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
1. Decapitalize errors.
2. Rename isValidName to checkPropertyName.
3. Make it return a specific error.
Suggested-by: Sebastiaan van Stijn <github@gone.nl>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Also, add a simple test and a benchmark (just out of sheer curiosity).
Benchmark results:
name old time/op new time/op delta
IsValidName-4 540ns ± 3% 45ns ± 1% -91.76% (p=0.008 n=5+5)
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Commit 1cd71dfd7 added isSecSuffix, but the same thing can be done
easily without a regex. This is faster and saves some init time and
memory.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
parseMountOption already returns way too many values, making the code
kind of hard to read.
Since all of the return values are used as is to populate the fields of
configs.Mount, let's change it to return (semi-)populated *configs.Mount
instead.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This makes the repeated calls to parseMountOptions faster,
and decreases the amount of garbage to collect.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
These two maps are the same, except that mountPropagationMapping
has an extra element with key of "" and value of 0. Since the
code already checks for f != 0, this extra element is not a problem.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Eliminate some of these allocations when starting runc:
> init github.com/opencontainers/runc/libcontainer/specconv @10 ms, 0.11 ms clock, 5408 bytes, 70 allocs
Most of this (4K) is the two regexes, which are left intact for now.
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>
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>
For files that end with _linux.go or _linux_test.go, there is no need to
specify linux build tag, as it is assumed from the file name.
In addition, rename libcontainer/notify_linux_v2.go -> libcontainer/notify_v2_linux.go
for the file name to make sense.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Handle ClosID parameter of IntelRdt. Makes it possible to use
pre-configured classes/ClosIDs and avoid running out of available IDs
which easily happens with per-container classes.
Remove validator checks for empty L3CacheSchema and MemBwSchema fields
in order to be able to leave them empty, and only specify ClosID for
a pre-configured class.
Signed-off-by: Markus Lehtonen <markus.lehtonen@intel.com>
In cases we have something like
if y != "" {
x = y
}
where both x and y are strings, and x was not set before,
it makes no sense to have a condition, as such code is
equivalent to mere
x = y
Simplify such cases by removing "if".
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This should result in no change when the error is printed, but make the
errors returned unwrappable, meaning errors.As and errors.Is will work.
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>
Commits 1f1e91b1a0 and 2192670a24
added validation for mountpoints to be an absolute path, to match the OCI
specs.
Unfortunately, the old behavior (accepting the path to be a relative path)
has been around for a long time, and although "not according to the spec",
various higher level runtimes rely on this behavior.
While higher level runtime have been updated to address this requirement,
there will be a transition period before all runtimes are updated to carry
these fixes.
This patch relaxes the validation, to generate a WARNING instead of failing,
allowing runtimes to update (but allowing them to update runc to the current
version, which includes security fixes).
We can remove this exception in a future patch release.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
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>
In case of rootless, cgroup2 mount is not possible (see [1] for more
details), so since commit 9c81440fb5 runc bind-mounts the whole
/sys/fs/cgroup into container.
Problem is, if cgroupns is enabled, /sys/fs/cgroup inside the container
is supposed to show the cgroup files for this cgroup, not the root one.
The fix is to pass through and use the cgroup path in case cgroup2
mount failed, cgroupns is enabled, and the path is non-empty.
Surely this requires the /sys/fs/cgroup mount in the spec, so modify
runc spec --rootless to keep it.
Before:
$ ./runc run aaa
# find /sys/fs/cgroup/ -type d
/sys/fs/cgroup
/sys/fs/cgroup/user.slice
/sys/fs/cgroup/user.slice/user-1000.slice
/sys/fs/cgroup/user.slice/user-1000.slice/user@1000.service
...
# ls -l /sys/fs/cgroup/cgroup.controllers
-r--r--r-- 1 nobody nogroup 0 Feb 24 02:22 /sys/fs/cgroup/cgroup.controllers
# wc -w /sys/fs/cgroup/cgroup.procs
142 /sys/fs/cgroup/cgroup.procs
# cat /sys/fs/cgroup/memory.current
cat: can't open '/sys/fs/cgroup/memory.current': No such file or directory
After:
# find /sys/fs/cgroup/ -type d
/sys/fs/cgroup/
# ls -l /sys/fs/cgroup/cgroup.controllers
-r--r--r-- 1 root root 0 Feb 24 02:43 /sys/fs/cgroup/cgroup.controllers
# wc -w /sys/fs/cgroup/cgroup.procs
2 /sys/fs/cgroup/cgroup.procs
# cat /sys/fs/cgroup/memory.current
577536
[1] https://github.com/opencontainers/runc/issues/2158
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Per OCI runtime spec, mount destination MUST be absolute. Let's check
that and return an error if not.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
utam0k