kata-agent capability requirements

kata-agent-capability.md

Capability	Operations Requiring It	Key Code Locations	init only?
CAP_SYS_ADMIN	Mount kernel pseudo-filesystems (proc, sysfs, devtmpfs, tmpfs, devpts)	mount.rs: INIT_ROOTFS_MOUNTS, baremount()	Yes
CAP_SYS_ADMIN	Mount cgroup hierarchies (v1 controllers + v2 unified)	mount.rs: cgroups_mount(), CGROUPS map	Yes
CAP_SYS_ADMIN	pivot_root() — switch container rootfs	rustjail/src/mount.rs:531: pivot_rootfs()	No
CAP_SYS_ADMIN	unshare() — create new IPC, UTS, PID, NET, MNT namespaces	namespace.rs:111, rustjail/src/container.rs:520, :375	No
CAP_SYS_ADMIN	setns() — join existing namespaces	rustjail/src/container.rs:371	No
CAP_SYS_ADMIN	Bind-mount namespace files to persist them	namespace.rs:121: baremount(..., MS_BIND|MS_REC, ...)	No
CAP_SYS_ADMIN	Bind-mount /etc/resolv.conf for DNS	network.rs:77: mount::mount(..., MS_BIND, ...)	No
CAP_SYS_ADMIN	Load seccomp filter without NoNewPrivileges	rustjail/src/container.rs:731: comment explicitly states CAP_SYS_ADMIN required	No
CAP_SYS_ADMIN	sethostname()	main.rs:675	Yes
CAP_SYS_ADMIN	Write to /sys/fs/cgroup/*/ (cgroupfs driver)	rustjail/src/cgroups/fs/mod.rs	No
CAP_SYS_ADMIN	RNDADDTOENTCNT + RNDRESEEDCRNG ioctls on /dev/random	random.rs:45-53: reseed_rng()	No
CAP_SYS_BOOT	reboot(RB_POWER_OFF) on exit	main.rs:352	Yes
CAP_SYS_MODULE	Load kernel modules via modprobe	rpc.rs:2253: load_kernel_module(), called from create_sandbox at rpc.rs:1342	No
CAP_MKNOD	Create device nodes inside container rootfs	rustjail/src/mount.rs:978: mknod_dev() → stat::mknod()	No
CAP_SETUID	setuid() to assume container process UID	rustjail/src/container.rs: child process credential setup	No
CAP_SETGID	setgid() to assume container process GID	rustjail/src/container.rs: child process credential setup	No
CAP_SETGID	setgroups() — set supplemental groups for container process	rustjail/src/container.rs:684	No
CAP_SETPCAP	Drop capabilities from bounding set for containers	rustjail/src/capabilities.rs:54-55: drop_privileges() → caps::drop(..., CapSet::Bounding, ...)	No
CAP_SETPCAP	Set ambient, inheritable, effective, permitted cap sets	rustjail/src/capabilities.rs:58-82	No
CAP_CHOWN	chown() on storage mount points (fsGroup/fsUID)	storage/mod.rs:387, storage/local_handler.rs:46	No
CAP_DAC_OVERRIDE	Write to sysfs device paths (online_device) during hotplug	device/mod.rs:609: fs::write(path, "1") on /sys/.../online	No
CAP_DAC_OVERRIDE	Access protected paths when creating/mounting storage	storage/ handlers, bind-mounting shared container dirs	No
CAP_NET_ADMIN	Manipulate network interfaces, routes, ARP via rtnetlink	netlink.rs: add_arp_neighbors(), route/interface handlers	No
CAP_NET_ADMIN	unshare(CLONE_NEWNET) — create network namespace	rustjail/src/container.rs: CloneFlags::CLONE_NEWNET	No
CAP_NET_ADMIN	Run iptables-save/iptables-restore, ip6tables	rpc.rs:114-121: get_iptables, set_iptables RPC handlers	No
CAP_NET_RAW	Raw socket creation for netlink operations	Used internally by rtnetlink library	No
CAP_SYS_RESOURCE	swapon() — enable swap device	rpc.rs:2172: libc::swapon() in do_add_swap() and do_add_swap_path()	No
CAP_SYS_RESOURCE	Set LimitNOFILE=1073741824 and other rlimits	kata-agent.service.in:18, container rlimit setup in rustjail	No
CAP_FOWNER	chmod()/chown() on files not owned by root (container rootfs setup)	rustjail/src/mount.rs: device and rootfs setup	No
CAP_FSETID	Preserve setuid/setgid bits on files when chowning	rustjail/src/mount.rs: container filesystem setup	No
CAP_KILL	Send signals to container processes in other UIDs	rustjail/src/container.rs: signal handling, setup_signal_handler	No
CAP_IPC_LOCK	Lock memory for sensitive attestation/confidential data	Used by attestation-agent child process management	No
CAP_SYS_PTRACE	process_vm_readv/access /proc/<pid>/ of other namespaced processes	rustjail/src/container.rs: reading container process state	No

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