From fb7b71b86f5591cc4bf83fcf4081634f4c2980aa Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Mon, 14 Nov 2022 23:56:52 +0100 Subject: [PATCH] contrib/apparmor: Merge pasta and passt profiles, update rules AppArmor resolves executable links before profile attachment rules are evaluated, so, as long as pasta is installed as a link to passt, there's no way to differentiate the two cases. Merge the two profiles and leave a TODO note behind, explaining two possible ways forward. Update the rules so that passt and pasta are actually usable, once the profile is installed. Most required changes are related to isolation and sandboxing features. Signed-off-by: Stefano Brivio --- contrib/apparmor/usr.bin.passt | 73 ++++++++++++++++++++++++---------- contrib/apparmor/usr.bin.pasta | 66 ------------------------------ 2 files changed, 51 insertions(+), 88 deletions(-) delete mode 100644 contrib/apparmor/usr.bin.pasta diff --git a/contrib/apparmor/usr.bin.passt b/contrib/apparmor/usr.bin.passt index a19fede..96b61ef 100644 --- a/contrib/apparmor/usr.bin.passt +++ b/contrib/apparmor/usr.bin.passt @@ -3,7 +3,10 @@ # PASST - Plug A Simple Socket Transport # for qemu/UNIX domain socket mode # -# contrib/apparmor/usr.bin.passt - AppArmor profile example/template for passt +# PASTA - Pack A Subtle Tap Abstraction +# for network namespace/tap device mode +# +# contrib/apparmor/usr.bin.passt - AppArmor profile for passt(1) and pasta(1) # # Copyright (c) 2022 Red Hat GmbH # Author: Stefano Brivio @@ -12,31 +15,29 @@ abi , include -/usr/bin/passt { - ### Alternatively: include - @{etc_ro}/ld.so.cache r, - /{usr/,}lib{,32,64}/ld-*.so r, - /{usr/,}lib{,32,64}/libc-*.so mr, - /{usr/,}lib/@{multiarch}/ld-*.so r, - /{usr/,}lib/@{multiarch}/libc-*.so mr, - /dev/null rw, # __daemon(), util.c - signal receive set=int peer=unconfined, - signal receive set=term peer=unconfined, - ### +profile passt /usr/bin/passt{,.avx2} flags=(attach_disconnected) { + ### Common rules for passt and pasta - ### Alternatively: include + include + + # Alternatively: include @{etc_ro}/resolv.conf r, # get_dns(), conf.c - ### - capability sys_admin, # sandbox(), passt.c - capability setpcap, # drop_caps(), util.c + capability net_bind_service, # isolation.c, conf.c + capability setuid, + capability setgid, + capability sys_admin, + capability setpcap, + capability net_admin, + capability sys_ptrace, - mount "" -> "/", # sandbox(), passt.c + / r, # isolate_prefork(), isolation.c + mount "" -> "/", mount "" -> "/tmp/", pivot_root "/tmp/" -> "/tmp/", umount "/", - network netlink raw, # netlink.c + network netlink raw, # nl_sock_init_do(), netlink.c network inet stream, # tcp.c network inet6 stream, @@ -46,14 +47,42 @@ include network unix stream, # tap.c - network unix dgram, # __openlog(), util.c + network unix dgram, # __openlog(), log.c - ### Alternatively: include + # Alternatively: include owner /tmp/** w, # tap_sock_unix_init(), pcap(), - # write_pidfile() - ### + # write_pidfile(), + # logfile_init() owner @{HOME}/** w, # pcap(), write_pidfile() /usr/bin/passt.avx2 ix, # arch_avx2_exec(), arch.c + + + ### Rules for pasta + ### + ### TODO: AppArmor doesn't give us the chance to attach a separate profile + ### depending on the executable symlink. That's possible with SELinux. Two + ### alternatives: implement that in AppArmor, or consider aa_change_hat(2). + ### With this, rules for passt(1) could be restricted significantly. Note that + ### the attach_disconnected flag is not needed for passt(1). + + @{PROC}/net/tcp r, # procfs_scan_listen(), util.c + @{PROC}/net/tcp6 r, + @{PROC}/net/udp r, + @{PROC}/net/udp6 r, + + @{run}/user/@{uid}/netns/* r, # pasta_open_ns(), pasta.c + + @{PROC}/[0-9]*/ns/net r, # pasta_wait_for_ns(), + @{PROC}/[0-9]*/ns/user r, # conf_pasta_ns() + + /dev/net/tun rw, # tap_ns_tun(), tap.c + + owner @{PROC}/@{pid}/gid_map w, # pasta_start_ns(), conf_ugid() + owner @{PROC}/@{pid}/setgroups w, + owner @{PROC}/@{pid}/uid_map rw, + + owner @{PROC}/sys/net/ipv4/ping_group_range w, # pasta_spawn_cmd(), pasta.c + /{usr/,}bin/** Ux, } diff --git a/contrib/apparmor/usr.bin.pasta b/contrib/apparmor/usr.bin.pasta deleted file mode 100644 index 844fcf3..0000000 --- a/contrib/apparmor/usr.bin.pasta +++ /dev/null @@ -1,66 +0,0 @@ -# SPDX-License-Identifier: AGPL-3.0-or-later -# -# PASTA - Pack A Subtle Tap Abstraction -# for network namespace/tap device mode -# -# contrib/apparmor/usr.bin.pasta - AppArmor profile example/template for pasta -# -# Copyright (c) 2022 Red Hat GmbH -# Author: Stefano Brivio - -abi , - -include - -/usr/bin/pasta flags=(attach_disconnected) { - include # Interactive shell - include - include - include - owner /proc/**/ns/user r, - / r, - capability sys_ptrace, # bash - capability dac_read_search, - capability dac_override, - @{etc_ro}/** r, - /usr/** r, - /lib/** r, - owner @{HOME}/** rw, - owner /tmp/** rw, - - /proc/*/net/tcp r, # procfs_scan_listen(), util.c - /proc/*/net/tcp6 r, - /proc/*/net/udp r, - /proc/*/net/udp6 r, - - /dev/net/tun rw, # tap_ns_tun(), tap.c - - capability net_admin, # for network namespace only - capability setpcap, # drop_caps(), util.c - capability sys_admin, # sandbox(), passt.c - - mount "" -> "/", # sandbox(), passt.c - mount "" -> "/tmp/", - pivot_root "/tmp/" -> "/tmp/", - umount "/", - - network netlink raw, # netlink.c - - network inet stream, # tcp.c - network inet6 stream, - - network inet dgram, # udp.c - network inet6 dgram, - - network unix stream, # tap.c - - network unix dgram, # __openlog(), util.c - - owner /proc/*/gid_map w, # pasta_setup_ns() - owner /proc/*/setgroups w, - owner /proc/*/uid_map w, - owner /proc/sys/net/ipv4/ping_group_range w, - /{usr/,}bin/** mrix, # spawning shell - - /usr/bin/pasta.avx2 ix, # arch_avx2_exec(), arch.c -}