Files
podman/test/system/410-selinux.bats
Daniel J Walsh 5b7dce8a3d Add support for confined users
The original SELinux support in Docker and Podman does not follow the
default SELinux rules for how label transitions are supposed to be
handled. Containers always switch their user and role to
system_u:system_r, rather then maintain the collers user and role.
For example
unconfined_u:unconfined_r:container_t:s0:c1,c2

Advanced SELinux administrators want to confine users but still allow
them to create containers from their role, but not allow them to launch
a privileged container like spc_t.

This means if a user running as
container_user_u:container_user_r:container_user_t:s0

Ran a container they would get

container_user_u:container_user_r:container_t:s0:c1,c2

If they run a privileged container they would run it with:

container_user_u:container_user_r:container_user_t:s0

If they want to force the label they would get an error

podman run --security-opt label=type:spc_t ...

Should fail. Because the container_user_r can not run with the spc_t.

SELinux rules would also prevent the user from forcing system_u user and
the sytem_r role.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Signed-off-by: Chris Evich <cevich@redhat.com>
2023-08-01 11:25:00 -04:00

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#!/usr/bin/env bats -*- bats -*-
#
# 410-selinux - podman selinux tests
#
load helpers
function check_label() {
skip_if_no_selinux
local args="$1"; shift # command-line args for run
# FIXME: it'd be nice to specify the command to run, e.g. 'ls -dZ /',
# but alpine ls (from busybox) doesn't support -Z
run_podman run --rm $args $IMAGE cat -v /proc/self/attr/current
# FIXME: on some CI systems, 'run --privileged' emits a spurious
# warning line about dup devices. Ignore it.
remove_same_dev_warning
local context="$output"
run id -Z
user=$(secon -u $output)
role=$(secon -r $output)
case "$args" in
# Containers that run automatically without SELinux transitions, run
# with the current role.
*--privileged*| *--pid=host* | *--ipc=host* | *"--security-opt label=disable"*)
is "$context" "$user:$role:.*" "Non SELinux separated containers role should always be the current user and role"
;;
# Containers that are confined or force the spc_t type default
# to running with the system_r role.
*)
is "$context" ".*_u:system_r:.*" "SELinux separated containers role should always be system_r"
;;
esac
# e.g. system_u:system_r:container_t:s0:c45,c745 -> "container_t"
type=$(cut -d: -f3 <<<"$context")
is "$type" "$1" "SELinux type"
if [ -n "$2" ]; then
# e.g. from the above example -> "s0:c45,c745"
range=$(cut -d: -f4,5 <<<"$context")
is "$range" "$2^@" "SELinux range"
fi
}
# bats test_tags=distro-integration
@test "podman selinux: confined container" {
check_label "" "container_t"
}
# FIXME #19376 - container-selinux broken -- bats test_tags=distro-integration
@test "podman selinux: container with label=disable" {
check_label "--security-opt label=disable" "spc_t"
}
# FIXME #19376 - container-selinux broken -- bats test_tags=distro-integration
@test "podman selinux: privileged container" {
check_label "--privileged" "spc_t"
}
@test "podman selinux: privileged --userns=host container" {
check_label "--privileged --userns=host" "spc_t"
}
# bats test_tags=distro-integration
@test "podman selinux: --ipc=host container" {
check_label "--ipc=host" "spc_t"
}
# bats test_tags=distro-integration
@test "podman selinux: init container" {
check_label "--systemd=always" "container_init_t"
}
# bats test_tags=distro-integration
@test "podman selinux: init container with --security-opt type" {
check_label "--systemd=always --security-opt=label=type:spc_t" "spc_t"
}
# bats test_tags=distro-integration
@test "podman selinux: init container with --security-opt level&type" {
check_label "--systemd=always --security-opt=label=level:s0:c1,c2 --security-opt=label=type:spc_t" "spc_t" "s0:c1,c2"
}
@test "podman selinux: init container with --security-opt level" {
check_label "--systemd=always --security-opt=label=level:s0:c1,c2" "container_init_t" "s0:c1,c2"
}
# FIXME #19376 - container-selinux broken -- bats test_tags=distro-integration
@test "podman selinux: pid=host" {
# FIXME this test fails when run rootless with runc:
# Error: container_linux.go:367: starting container process caused: process_linux.go:495: container init caused: readonly path /proc/asound: operation not permitted: OCI permission denied
if is_rootless; then
runtime=$(podman_runtime)
test "$runtime" == "crun" \
|| skip "runtime is $runtime; this test requires crun"
fi
check_label "--pid=host" "spc_t"
}
@test "podman selinux: container with overridden range" {
check_label "--security-opt label=level:s0:c1,c2" "container_t" "s0:c1,c2"
}
@test "podman selinux: inspect kvm labels" {
skip_if_no_selinux
skip_if_remote "runtime flag is not passed over remote"
tmpdir=$PODMAN_TMPDIR/kata-test
mkdir -p $tmpdir
KATA=${tmpdir}/kata-runtime
ln -s /bin/true ${KATA}
run_podman create --runtime=${KATA} --name myc $IMAGE
run_podman inspect --format='{{ .ProcessLabel }}' myc
is "$output" ".*container_kvm_t"
run_podman rm myc
}
# pr #6752
@test "podman selinux: inspect multiple labels" {
skip_if_no_selinux
run_podman run -d --name myc \
--security-opt seccomp=unconfined \
--security-opt label=type:spc_t \
--security-opt label=level:s0 \
$IMAGE top
run_podman inspect --format='{{ .HostConfig.SecurityOpt }}' myc
is "$output" "[label=type:spc_t,label=level:s0 seccomp=unconfined]" \
"'podman inspect' preserves all --security-opts"
run_podman rm -t 0 -f myc
}
# Sharing context between two containers not in a pod
# These tests were piggybacked in with #7902, but are not actually related
@test "podman selinux: shared context in (some) namespaces" {
skip_if_no_selinux
# rootless users have no usable cgroups with cgroupsv1, so containers
# must use a pid namespace and not join an existing one.
skip_if_rootless_cgroupsv1
if [[ $(podman_runtime) == "runc" ]]; then
skip "some sort of runc bug, not worth fixing (issue 11784, wontfix)"
fi
run_podman run -d --name myctr $IMAGE top
run_podman exec myctr cat -v /proc/self/attr/current
context_c1="$output"
# --ipc container
run_podman run --name myctr2 --ipc container:myctr $IMAGE cat -v /proc/self/attr/current
is "$output" "$context_c1" "new container, run with ipc of existing one "
# --pid container
run_podman run --rm --pid container:myctr $IMAGE cat -v /proc/self/attr/current
is "$output" "$context_c1" "new container, run with --pid of existing one "
# net NS: do not share context
run_podman run --rm --net container:myctr $IMAGE cat -v /proc/self/attr/current
assert "$output" != "$context_c1" \
"run --net : context should != context of running container"
# The 'myctr2' above was not run with --rm, so it still exists, and
# we can't remove the original container until this one is gone.
run_podman stop -t 0 myctr
run_podman 125 rm myctr
is "$output" "Error: container .* has dependent containers"
# We have to do this in two steps: even if ordered as 'myctr2 myctr',
# podman will try the removes in random order, which fails if it
# tries myctr first.
run_podman rm myctr2
run_podman rm myctr
}
# pr #7902 - containers in pods should all run under same context
# bats test_tags=distro-integration
@test "podman selinux: containers in pods share full context" {
skip_if_no_selinux
# unique pod name helps when tracking down failure in journal
local podname=myselinuxpod_do_share
# We don't need a fullblown pause container; avoid pulling the k8s one
run_podman pod create --name $podname \
--infra-image $IMAGE \
--infra-command /home/podman/pause
# Get baseline
run_podman run --rm --pod $podname $IMAGE cat -v /proc/self/attr/current
context_c1="$output"
# Prior to #7902, the labels (':c123,c456') would be different
run_podman run --rm --pod $podname $IMAGE cat -v /proc/self/attr/current
is "$output" "$context_c1" "SELinux context of 2nd container matches 1st"
# What the heck. Try a third time just for extra confidence
run_podman run --rm --pod $podname $IMAGE cat -v /proc/self/attr/current
is "$output" "$context_c1" "SELinux context of 3rd container matches 1st"
run_podman pod rm -f -t0 $podname
}
# more pr #7902
@test "podman selinux: containers in --no-infra pods do not share context" {
skip_if_no_selinux
# unique pod name helps when tracking down failure in journal
local podname=myselinuxpod_dont_share
# We don't need a fullblown pause container; avoid pulling the k8s one
run_podman pod create --name $podname --infra=false
# Get baseline
run_podman run --rm --pod $podname $IMAGE cat -v /proc/self/attr/current
context_c1="$output"
# Even after #7902, labels (':c123,c456') should be different
run_podman run --rm --pod $podname $IMAGE cat -v /proc/self/attr/current
assert "$output" != "$context_c1" \
"context of two separate containers should be different"
run_podman pod rm -f -t0 $podname
}
# #8946 - better diagnostics for nonexistent attributes
@test "podman with nonexistent labels" {
skip_if_no_selinux
# runc and crun emit different diagnostics
runtime=$(podman_runtime)
case "$runtime" in
# crun 0.20.1 changes the error message
# from /proc/thread-self/attr/exec`: .* unable to assign
# to /proc/self/attr/keycreate`: .* unable to process
crun) expect="\`/proc/.*\`: OCI runtime error: unable to \(assign\|process\) security attribute" ;;
# runc 1.1 changed the error message because of new selinux pkg that uses standard os.PathError, see
# https://github.com/opencontainers/selinux/pull/148/commits/a5dc47f74c56922d58ead05d1fdcc5f7f52d5f4e
# from failed to set /proc/self/attr/keycreate on procfs
# to write /proc/self/attr/keycreate: invalid argument
runc) expect=".*: \(failed to set\|write\) /proc/self/attr/keycreate.*" ;;
*) skip "Unknown runtime '$runtime'";;
esac
# The '.*' in the error below is for dealing with podman-remote, which
# includes "error preparing container <sha> for attach" in output.
run_podman 126 run --rm --security-opt label=type:foo.bar $IMAGE true
is "$output" "Error.*: $expect" "podman emits useful diagnostic on failure"
}
# bats test_tags=distro-integration
@test "podman selinux: check relabel" {
skip_if_no_selinux
LABEL="system_u:object_r:tmp_t:s0"
RELABEL="system_u:object_r:container_file_t:s0"
tmpdir=$PODMAN_TMPDIR/vol
mkdir -p $tmpdir
chcon -vR ${LABEL} $tmpdir
ls -Z $tmpdir
run_podman run --rm -v $tmpdir:/test $IMAGE cat /proc/self/attr/current
run ls -dZ ${tmpdir}
is "$output" "${LABEL} ${tmpdir}" "No Relabel Correctly"
run_podman run --rm -v $tmpdir:/test:z --security-opt label=disable $IMAGE cat /proc/self/attr/current
run ls -dZ $tmpdir
is "$output" "${RELABEL} $tmpdir" "Privileged Relabel Correctly"
run_podman run --rm -v $tmpdir:/test:z --privileged $IMAGE cat /proc/self/attr/current
run ls -dZ $tmpdir
is "$output" "${RELABEL} $tmpdir" "Privileged Relabel Correctly"
run_podman run --name label -v $tmpdir:/test:Z $IMAGE cat /proc/self/attr/current
level=$(secon -l $output)
run ls -dZ $tmpdir
is "$output" "system_u:object_r:container_file_t:$level $tmpdir" \
"Confined Relabel Correctly"
# podman-remote has no 'unshare'
if is_rootless && ! is_remote; then
run_podman unshare touch $tmpdir/test1
# Relabel entire directory
run_podman unshare chcon system_u:object_r:usr_t:s0 $tmpdir
run_podman start --attach label
newlevel=$(secon -l $output)
is "$level" "$newlevel" "start should relabel with same SELinux labels"
run ls -dZ $tmpdir
is "$output" "system_u:object_r:container_file_t:$level $tmpdir" \
"Confined Relabel Correctly"
run ls -dZ $tmpdir/test1
is "$output" "system_u:object_r:container_file_t:$level $tmpdir/test1" \
"Start did not Relabel"
# Relabel only file in subdir
run_podman unshare chcon system_u:object_r:usr_t:s0 $tmpdir/test1
run_podman start --attach label
newlevel=$(secon -l $output)
is "$level" "$newlevel" "start should use same SELinux labels"
run ls -dZ $tmpdir/test1
is "$output" "system_u:object_r:usr_t:s0 $tmpdir/test1" \
"Start did not Relabel"
fi
run_podman rm label
run_podman run --rm -v $tmpdir:/test:z $IMAGE cat /proc/self/attr/current
run ls -dZ $tmpdir
is "$output" "${RELABEL} $tmpdir" "Shared Relabel Correctly"
}
@test "podman selinux nested" {
skip_if_no_selinux
ROOTCONTEXT='rw,rootcontext="system_u:object_r:container_file_t:s0:c1,c2"'
SELINUXMNT="selinuxfs.*(rw,nosuid,noexec,relatime)"
SELINUXMNT="tmpfs.*selinux.*\(ro"
run_podman run --rm --security-opt label=level:s0:c1,c2 $IMAGE mount
assert "$output" !~ "${ROOTCONTEXT}" "Don't use rootcontext"
assert "$output" =~ "${SELINUXMNT}" "Mount SELinux file system readwrite"
run_podman run --rm --security-opt label=nested --security-opt label=level:s0:c1,c2 $IMAGE mount
assert "$output" =~ "${ROOTCONTEXT}" "Uses rootcontext"
assert "$output" =~ "${SELINUXMNT}" "Mount SELinux file system readwrite"
}
@test "podman EnableLabeledUsers" {
skip_if_no_selinux
overrideConf=$PODMAN_TMPDIR/containers.conf
cat >$overrideConf <<EOF
[Containers]
label_users=true
EOF
run id -Z
user=$(secon -u $output)
role=$(secon -r $output)
CONTAINERS_CONF_OVERRIDE=$overrideConf run_podman run $IMAGE cat /proc/self/attr/current
level=$(secon -l $output)
id -Z
is "$output" "$user:$role:container_t:$level" "Confined label Correctly"
CONTAINERS_CONF_OVERRIDE=$overrideConf run_podman run --rm --name label --security-opt label=role:system_r $IMAGE cat /proc/self/attr/current
level=$(secon -l $output)
is "$output" "$user:system_r:container_t:$level" "Confined with role override label Correctly"
}
# vim: filetype=sh