When writing netlink messages, it is possible to have a byte array
larger than UINT16_MAX which would result in the length field
overflowing and allowing user-controlled data to be parsed as control
characters (such as creating custom mount points, changing which set of
namespaces to allow, and so on).
Co-authored-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Since commit 7296dc1712, type intelRdtData is only used by tests,
and since commit 79d292b9f, its only member is config.
Change the test to use config directly, and remove the type.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
It never returns any error, so let's drop it (in case it needs to be
re-added, it is easy to do so).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Those were never used (ctx was added by the initial commit, and
error was added by commit 25fd4a6757).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This function never returned anything other than nil, and its return
value is discarded since it is only called from defer.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This is not used since commit 5e7b48f7c0 (23 Mar 2017).
In case there are external users, they should switch to
opencontainers/selinux.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Move test case comments to doc strings, and use t.Run.
Suggested-by: Sebastiaan van Stijn <github@gone.nl>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
There is no need to run hooks when `Config.Hooks` is just an empty map,
(dlv) p p.config.Config.Hooks
github.com/opencontainers/runc/libcontainer/configs.Hooks []
Signed-off-by: Dave Chen <dave.chen@arm.com>
1. Instead of distinguishing between errors and warnings, let's treat all
errors as warnings, thus simplifying the code. This changes the
function behaviour for input like hugepages-BadNumberKb --
previously, the error from Atoi("BadNumber") was considered fatal,
now it's just another warnings.
2. Move the warning logging to HugePageSizes, thus simplifying the test
case, which no longer needs to read what logrus writes. Note that we
do not want to log all the warnings (as chances are very low we'll
get any, and if we do this means the code need to be updated), only
the first one.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
I have noticed that libct/cg/fs allocates 8K during init on every runc
execution:
> init github.com/opencontainers/runc/libcontainer/cgroups/fs @1.5 ms, 0.028 ms clock, 8512 bytes, 13 allocs
Apparently this is caused by global HugePageSizes variable init, which
is only used from GetStats (i.e. it is never used by runc itself).
Remove it, and use HugePageSizes() directly instead. Make it init-once,
so that GetStats (which, I guess, is periodically called by kubernetes)
does not re-read huge page sizes over and over.
This also removes 12 allocs and 8K from libct/cg/fs init section:
> $ time GODEBUG=inittrace=1 ./runc --help 2>&1 | grep cgroups/fs
> init github.com/opencontainers/runc/libcontainer/cgroups/fs @1.5 ms, 0.003 ms clock, 16 bytes, 1 allocs
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
1. Since GetHugePageSize do not have any external users (checked by
sourcegraph), and no internal user ever uses its second return value
(the error), let's drop it.
2. Rename GetHugePageSize -> HugePageSizes (drop the Get prefix as per
Go guidelines, add suffix since we return many sizes).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.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>
As reported in [1], in a case where read-only fuse (sshfs) mount
is used as a volume without specifying ro flag, the kernel fails
to remount it (when adding various flags such as nosuid and nodev),
returning EPERM.
Here's the relevant strace line:
> [pid 333966] mount("/tmp/bats-run-PRVfWc/runc.RbNv8g/bundle/mnt", "/proc/self/fd/7", 0xc0001e9164, MS_NOSUID|MS_NODEV|MS_REMOUNT|MS_BIND|MS_REC, NULL) = -1 EPERM (Operation not permitted)
I was not able to reproduce it with other read-only mounts as the source
(tried tmpfs, read-only bind mount, and an ext2 mount), so somehow this
might be specific to fuse.
The fix is to check whether the source has RDONLY flag, and retry the
remount with this flag added.
A test case (which was kind of hard to write) is added, and it fails
without the fix. Note that rootless user need to be able to ssh to
rootless@localhost in order to sshfs to work -- amend setup scripts
to make it work, and skip the test if the setup is not working.
[1] https://github.com/containers/podman/issues/12205
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The staticcheck linter points out that the err != nil comparison
after system.Exec is always true:
> libcontainer/standard_init_linux.go#L253
> SA4023: this comparison is always true (staticcheck)
> libcontainer/system/linux.go#L43
> SA4023(related information): github.com/opencontainers/runc/libcontainer/system.Exec never returns a nil interface value (staticcheck)
Indeed, Exec either returns an error or does not return at all.
Remove the (useless) check.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.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>
Commit fb4c27c4b7 (went into v1.0.0-rc93) fixed a bug with
read-only tmpfs, but introduced a bug with read-only /dev.
This happens because /dev is a tmpfs mount and is therefore remounted
read-only a bit earlier than before.
To fix,
1. Revert the part of the above commit which remounts all tmpfs mounts
as read-only in mountToRootfs.
2. Reuse finalizeRootfs (which is already used to remount /dev
read-only) to also remount all ro tmpfs mounts that were previously
mounted rw in mountPropagate.
3. Remove the break in finalizeRootfs, as now we have more than one
mount to care about.
4. Reorder the if statements in finalizeRootfs to perform the fast check
(for ro flag) first, and compare the strings second. Since /dev is
most probably also a tmpfs mount, do the m.Device check first.
Add a test case to validate the fix and prevent future regressions;
make sure it fails before the fix:
✗ runc run [ro /dev mount]
(in test file tests/integration/mounts.bats, line 45)
`[ "$status" -eq 0 ]' failed
runc spec (status=0):
runc run test_busybox (status=1):
time="2021-11-12T12:19:48-08:00" level=error msg="runc run failed: unable to start container process: error during container init: error mounting \"devpts\" to rootfs at \"/dev/pts\": mkdir /tmp/bats-run-VJXQk7/runc.0Fj70w/bundle/rootfs/dev/pts: read-only file system"
Fixes: fb4c27c4b7
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>
Aleksa Sarai