# Author: Jamie Strandboge #include /snap/core/5897/usr/lib/snapd/snap-confine (attach_disconnected) { # Include any additional files that snapd chose to generate. # - for $HOME on NFS # - for $HOME on encrypted media # # Those are discussed on https://forum.snapcraft.io/t/snapd-vs-upstream-kernel-vs-apparmor # and https://forum.snapcraft.io/t/snaps-and-nfs-home/ #include "/var/lib/snapd/apparmor/snap-confine" # We run privileged, so be fanatical about what we include and don't use # any abstractions /etc/ld.so.cache r, /etc/ld.so.preload r, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}ld-*.so mrix, # libc, you are funny /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libc{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libpthread{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libreadline{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}librt{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libgcc_s.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libncursesw{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libresolv{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libselinux.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libpcre.so* mr, # normal libs in order /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libapparmor.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libcgmanager.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libdl{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libnih.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libnih-dbus.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libdbus-1.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libudev.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libseccomp.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libcap.so* mr, /snap/core/5897/usr/lib/snapd/snap-confine mr, /dev/null rw, /dev/full rw, /dev/zero rw, /dev/random r, /dev/urandom r, /dev/pts/[0-9]* rw, /dev/tty rw, # cgroup: devices capability sys_admin, capability dac_read_search, capability dac_override, /sys/fs/cgroup/devices/snap{,py}.*/ w, /sys/fs/cgroup/devices/snap{,py}.*/tasks w, /sys/fs/cgroup/devices/snap{,py}.*/devices.{allow,deny} w, # cgroup: freezer # Allow creating per-snap cgroup freezers and adding snap command (task) # invocations to the freezer. This allows for reliably enumerating all # running tasks for the snap. In addition, allow enumerating processes in # the cgroup to determine if it is occupied. /sys/fs/cgroup/freezer/ r, /sys/fs/cgroup/freezer/snap.*/ w, /sys/fs/cgroup/freezer/snap.*/tasks w, /sys/fs/cgroup/freezer/snap.*/cgroup.procs r, # querying udev /etc/udev/udev.conf r, /sys/**/uevent r, /usr/lib/snapd/snap-device-helper ixr, # drop /{,usr/}lib/udev/snappy-app-dev ixr, # drop /run/udev/** rw, /{,usr/}bin/tr ixr, /usr/lib/locale/** r, /usr/lib/@{multiarch}/gconv/gconv-modules r, /usr/lib/@{multiarch}/gconv/gconv-modules.cache r, # priv dropping capability setuid, capability setgid, # changing profile @{PROC}/[0-9]*/attr/exec w, # Reading current profile @{PROC}/[0-9]*/attr/current r, # Reading available filesystems @{PROC}/filesystems r, # To find where apparmor is mounted @{PROC}/[0-9]*/mounts r, # To find if apparmor is enabled /sys/module/apparmor/parameters/enabled r, # Don't allow changing profile to unconfined or profiles that start with # '/'. Use 'unsafe' to support snap-exec on armhf and its reliance on # the environment for determining the capabilities of the architecture. # 'unsafe' is ok here because the kernel will have already cleared the # environment as part of launching snap-confine with # CAP_SYS_ADMIN. change_profile unsafe /** -> [^u/]**, change_profile unsafe /** -> u[^n]**, change_profile unsafe /** -> un[^c]**, change_profile unsafe /** -> unc[^o]**, change_profile unsafe /** -> unco[^n]**, change_profile unsafe /** -> uncon[^f]**, change_profile unsafe /** -> unconf[^i]**, change_profile unsafe /** -> unconfi[^n]**, change_profile unsafe /** -> unconfin[^e]**, change_profile unsafe /** -> unconfine[^d]**, change_profile unsafe /** -> unconfined?**, # allow changing to a few not caught above change_profile unsafe /** -> {u,un,unc,unco,uncon,unconf,unconfi,unconfin,unconfine}, # LP: #1446794 - when this bug is fixed, change the above to: # deny change_profile unsafe /** -> {unconfined,/**}, # change_profile unsafe /** -> **, # reading seccomp filters /{tmp/snap.rootfs_*/,}var/lib/snapd/seccomp/bpf/*.bin r, # ensuring correct permissions in sc_quirk_create_writable_mimic /{tmp/snap.rootfs_*/,}var/lib/ rw, # LP: #1668659 mount options=(rw rbind) /snap/ -> /snap/, mount options=(rw rshared) -> /snap/, # boostrapping the mount namespace mount options=(rw rshared) -> /, mount options=(rw bind) /tmp/snap.rootfs_*/ -> /tmp/snap.rootfs_*/, mount options=(rw unbindable) -> /tmp/snap.rootfs_*/, # the next line is for classic system mount options=(rw rbind) /snap/*/*/ -> /tmp/snap.rootfs_*/, # the next line is for core system mount options=(rw rbind) / -> /tmp/snap.rootfs_*/, # all of the constructed rootfs is a rslave mount options=(rw rslave) -> /tmp/snap.rootfs_*/, # bidirectional mounts (for both classic and core) # NOTE: this doesn't capture the MERGED_USR configuration option so that # when a distro with merged /usr and / that uses apparmor shows up it # should be handled here. /{,run/}media/ w, mount options=(rw rbind) /{,run/}media/ -> /tmp/snap.rootfs_*/{,run/}media/, /run/netns/ w, mount options=(rw rbind) /run/netns/ -> /tmp/snap.rootfs_*/run/netns/, # unidirectional mounts (only for classic system) mount options=(rw rbind) /dev/ -> /tmp/snap.rootfs_*/dev/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/dev/, mount options=(rw rbind) /etc/ -> /tmp/snap.rootfs_*/etc/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/etc/, mount options=(rw rbind) /home/ -> /tmp/snap.rootfs_*/home/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/home/, mount options=(rw rbind) /root/ -> /tmp/snap.rootfs_*/root/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/root/, mount options=(rw rbind) /proc/ -> /tmp/snap.rootfs_*/proc/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/proc/, mount options=(rw rbind) /sys/ -> /tmp/snap.rootfs_*/sys/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/sys/, mount options=(rw rbind) /tmp/ -> /tmp/snap.rootfs_*/tmp/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/tmp/, mount options=(rw rbind) /var/lib/snapd/ -> /tmp/snap.rootfs_*/var/lib/snapd/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/var/lib/snapd/, mount options=(rw rbind) /var/snap/ -> /tmp/snap.rootfs_*/var/snap/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/var/snap/, mount options=(rw rbind) /var/tmp/ -> /tmp/snap.rootfs_*/var/tmp/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/var/tmp/, mount options=(rw rbind) /run/ -> /tmp/snap.rootfs_*/run/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/run/, mount options=(rw rbind) /var/lib/extrausers/ -> /tmp/snap.rootfs_*/var/lib/extrausers/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/var/lib/extrausers/, mount options=(rw rbind) {,/usr}/lib{,32,64,x32}/modules/ -> /tmp/snap.rootfs_*{,/usr}/lib/modules/, mount options=(rw rslave) -> /tmp/snap.rootfs_*{,/usr}/lib/modules/, mount options=(rw rbind) /var/log/ -> /tmp/snap.rootfs_*/var/log/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/var/log/, mount options=(rw rbind) /usr/src/ -> /tmp/snap.rootfs_*/usr/src/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/usr/src/, mount options=(rw rbind) /mnt/ -> /tmp/snap.rootfs_*/mnt/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/mnt/, # allow making host snap-exec available inside base snaps mount options=(rw bind) /usr/lib/snapd/ -> /tmp/snap.rootfs_*/usr/lib/snapd/, mount options=(rw slave) -> /tmp/snap.rootfs_*/usr/lib/snapd/, # allow making re-execed host snap-exec available inside base snaps mount options=(ro bind) /snap/core/*/usr/lib/snapd/ -> /tmp/snap.rootfs_*/usr/lib/snapd/, # allow making snapd snap tools available inside base snaps mount options=(ro bind) /snap/snapd/*/usr/lib/snapd/ -> /tmp/snap.rootfs_*/usr/lib/snapd/, mount options=(rw bind) /usr/bin/snapctl -> /tmp/snap.rootfs_*/usr/bin/snapctl, mount options=(rw slave) -> /tmp/snap.rootfs_*/usr/bin/snapctl, # /etc/alternatives (classic) mount options=(rw bind) /snap/*/*/etc/alternatives/ -> /tmp/snap.rootfs_*/etc/alternatives/, mount options=(rw bind) /snap/*/*/etc/ssl/ -> /tmp/snap.rootfs_*/etc/ssl/, mount options=(rw bind) /snap/*/*/etc/nsswitch.conf -> /tmp/snap.rootfs_*/etc/nsswitch.conf, # /etc/alternatives (core) mount options=(rw bind) /etc/alternatives/ -> /tmp/snap.rootfs_*/etc/alternatives/, mount options=(rw slave) -> /tmp/snap.rootfs_*/etc/alternatives/, mount options=(rw slave) -> /tmp/snap.rootfs_*/etc/ssl/, mount options=(rw slave) -> /tmp/snap.rootfs_*/etc/nsswitch.conf, # the /snap directory mount options=(rw rbind) /snap/ -> /tmp/snap.rootfs_*/snap/, mount options=(rw rslave) -> /tmp/snap.rootfs_*/snap/, # pivot_root preparation and execution mount options=(rw bind) /tmp/snap.rootfs_*/var/lib/snapd/hostfs/ -> /tmp/snap.rootfs_*/var/lib/snapd/hostfs/, mount options=(rw private) -> /tmp/snap.rootfs_*/var/lib/snapd/hostfs/, # pivot_root mediation in AppArmor is not complete. See LP: #1791711 pivot_root, # cleanup umount /var/lib/snapd/hostfs/tmp/snap.rootfs_*/, umount /var/lib/snapd/hostfs/sys/, umount /var/lib/snapd/hostfs/dev/, umount /var/lib/snapd/hostfs/proc/, mount options=(rw rslave) -> /var/lib/snapd/hostfs/, # set up user mount namespace mount options=(rslave) -> /, # Allow reading the os-release file (possibly a symlink to /usr/lib). /{etc/,usr/lib/}os-release r, # set up snap-specific private /tmp dir capability chown, /tmp/ w, /tmp/snap.*/ w, /tmp/snap.*/tmp/ w, mount options=(rw private) -> /tmp/, mount options=(rw bind) /tmp/snap.*/tmp/ -> /tmp/, mount fstype=devpts options=(rw) devpts -> /dev/pts/, mount options=(rw bind) /dev/pts/ptmx -> /dev/ptmx, # for bind mounting mount options=(rw bind) /dev/pts/ptmx -> /dev/pts/ptmx, # for bind mounting under LXD # Workaround for LP: #1584456 on older kernels that mistakenly think # /dev/pts/ptmx needs a trailing '/' mount options=(rw bind) /dev/pts/ptmx/ -> /dev/ptmx/, mount options=(rw bind) /dev/pts/ptmx/ -> /dev/pts/ptmx/, # for running snaps on classic /snap/ r, /snap/** r, /snap/ r, /snap/** r, # NOTE: at this stage the /snap directory is stable as we have called # pivot_root already. # nvidia handling, glob needs /usr/** and the launcher must be # able to bind mount the nvidia dir /sys/module/nvidia/version r, /sys/**/drivers/nvidia{,_*}/* r, /sys/**/nvidia*/uevent r, /sys/module/nvidia{,_*}/* r, /dev/nvidia[0-9]* r, /dev/nvidiactl r, /dev/nvidia-uvm r, /usr/** r, mount options=(rw bind) /usr/lib{,32}/nvidia-*/ -> /{tmp/snap.rootfs_*/,}var/lib/snapd/lib/gl{,32}/, mount options=(rw bind) /usr/lib{,32}/nvidia-*/ -> /{tmp/snap.rootfs_*/,}var/lib/snapd/lib/gl{,32}/, /tmp/snap.rootfs_*/var/lib/snapd/lib/gl{,32}/{,*} w, mount fstype=tmpfs options=(rw nodev noexec) none -> /tmp/snap.rootfs_*/var/lib/snapd/lib/gl{,32}/, mount options=(remount ro bind) -> /tmp/snap.rootfs_*/var/lib/snapd/lib/gl{,32}/, # Vulkan support /tmp/snap.rootfs_*/var/lib/snapd/lib/vulkan/{,*} w, mount fstype=tmpfs options=(rw nodev noexec) none -> /tmp/snap.rootfs_*/var/lib/snapd/lib/vulkan/, mount options=(remount ro bind) -> /tmp/snap.rootfs_*/var/lib/snapd/lib/vulkan/, # GLVND EGL vendor /tmp/snap.rootfs_*/var/lib/snapd/lib/glvnd/{,*} w, mount fstype=tmpfs options=(rw nodev noexec) none -> /tmp/snap.rootfs_*/var/lib/snapd/lib/glvnd/, mount options=(remount ro bind) -> /tmp/snap.rootfs_*/var/lib/snapd/lib/glvnd/, # create gl dirs as needed /tmp/snap.rootfs_*/ r, /tmp/snap.rootfs_*/var/ r, /tmp/snap.rootfs_*/var/lib/ r, /tmp/snap.rootfs_*/var/lib/snapd/ r, /tmp/snap.rootfs_*/var/lib/snapd/lib/ r, /tmp/snap.rootfs_*/var/lib/snapd/lib/gl{,32}/ r, /tmp/snap.rootfs_*/var/lib/snapd/lib/gl{,32}/** rw, /tmp/snap.rootfs_*/var/lib/snapd/lib/vulkan/ r, /tmp/snap.rootfs_*/var/lib/snapd/lib/vulkan/** rw, /tmp/snap.rootfs_*/var/lib/snapd/lib/glvnd/ r, /tmp/snap.rootfs_*/var/lib/snapd/lib/glvnd/** rw, # for chroot on steroids, we use pivot_root as a better chroot that makes # apparmor rules behave the same on classic and outside of classic. # for creating the user data directories: ~/snap, ~/snap/ and # ~/snap// / r, @{HOMEDIRS}/ r, # These should both have 'owner' match but due to LP: #1466234, we can't # yet @{HOME}/ r, @{HOME}/snap/{,*/,*/*/} rw, # for creating the user shared memory directories /{dev,run}/{,shm/} r, # This should both have 'owner' match but due to LP: #1466234, we can't yet /{dev,run}/shm/{,*/,*/*/} rw, # for creating the user XDG_RUNTIME_DIR: /run/user, /run/user/UID and # /run/user/UID/ /run/user/{,[0-9]*/,[0-9]*/*/} rw, # Workaround https://launchpad.net/bugs/359338 until upstream handles # stacked filesystems generally. # encrypted ~/.Private and old-style encrypted $HOME @{HOME}/.Private/ r, @{HOME}/.Private/** mrixwlk, # new-style encrypted $HOME @{HOMEDIRS}/.ecryptfs/*/.Private/ r, @{HOMEDIRS}/.ecryptfs/*/.Private/** mrixwlk, # Allow snap-confine to move to the void /var/lib/snapd/void/ r, # Allow snap-confine to read snap contexts /var/lib/snapd/context/snap.* r, # Allow snap-confine to unmount stale mount namespaces. umount /run/snapd/ns/*.mnt, /run/snapd/ns/snap.*.fstab w, # Required to correctly unmount bound mount namespace. # See LP: #1735459 for details. umount /, # Support for the quirk system /var/ r, /var/lib/ r, /var/lib/** rw, /tmp/ r, /tmp/snapd.quirks_*/ rw, mount options=(move) /var/lib/snapd/ -> /tmp/snapd.quirks_*/, mount fstype=tmpfs options=(rw nodev nosuid) none -> /var/lib/, mount options=(ro rbind) /snap/{,ubuntu-}core/*/var/lib/** -> /var/lib/**, umount /var/lib/snapd/, mount options=(move) /tmp/snapd.quirks_*/ -> /var/lib/snapd/, # On classic systems with a setuid root snap-confine when run by non-root # user, the mimic_dir is created with the gid of the calling user (ie, # not '0') so when setting the permissions (chmod) of the mimicked # directory to that of the reference directory, a CAP_FSETID is triggered. # snap-confine sets the directory up correctly, so simply silence the # denial since we don't want to grant the capability as a whole to # snap-confine. deny capability fsetid, # support for the LXD quirk mount options=(rw rbind nodev nosuid noexec) /var/lib/snapd/hostfs/var/lib/lxd/ -> /var/lib/lxd/, /var/lib/lxd/ w, /var/lib/snapd/hostfs/var/lib/lxd r, # support for locking /run/snapd/lock/ rw, /run/snapd/lock/*.lock rwk, # support for the mount namespace sharing capability sys_ptrace, # allow snap-confine to read /proc/1/ns/mnt ptrace read peer=unconfined, # https://forum.snapcraft.io/t/custom-kernel-error-on-readlinkat-in-mount-namespace/6097/21 ptrace trace peer=unconfined, mount options=(rw rbind) /run/snapd/ns/ -> /run/snapd/ns/, mount options=(private) -> /run/snapd/ns/, / rw, /run/ rw, /run/snapd/ rw, /run/snapd/ns/ rw, /run/snapd/ns/*.lock rwk, /run/snapd/ns/*.mnt rw, ptrace (read, readby, tracedby) peer=/snap/core/5897/usr/lib/snapd/snap-confine//mount-namespace-capture-helper, @{PROC}/*/mountinfo r, capability sys_chroot, capability sys_admin, signal (send, receive) set=(abrt) peer=/snap/core/5897/usr/lib/snapd/snap-confine, signal (send) set=(int) peer=/snap/core/5897/usr/lib/snapd/snap-confine//mount-namespace-capture-helper, signal (send, receive) set=(int, alrm, exists) peer=/snap/core/5897/usr/lib/snapd/snap-confine, signal (receive) set=(exists) peer=/snap/core/5897/usr/lib/snapd/snap-confine//mount-namespace-capture-helper, # workaround for linux 4.13/upstream, see # https://forum.snapcraft.io/t/snapd-2-27-6-2-in-debian-sid-blocked-on-apparmor-in-kernel-4-13-0-1/2813/3 ptrace (trace, tracedby) peer=/snap/core/5897/usr/lib/snapd/snap-confine, # For aa_change_hat() to go into ^mount-namespace-capture-helper @{PROC}/[0-9]*/attr/current w, ^mount-namespace-capture-helper (attach_disconnected) { # We run privileged, so be fanatical about what we include and don't use # any abstractions /etc/ld.so.cache r, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}ld-*.so mrix, # libc, you are funny /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libc{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libpthread{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libreadline{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}librt{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libgcc_s.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libncursesw{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libresolv{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libselinux.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libpcre.so* mr, # normal libs in order /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libapparmor.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libcgmanager.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libdl{,-[0-9]*}.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libnih.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libnih-dbus.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libdbus-1.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libudev.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libseccomp.so* mr, /{,usr/}lib{,32,64,x32}/{,@{multiarch}/}libcap.so* mr, /snap/core/5897/usr/lib/snapd/snap-confine mr, /dev/null rw, /dev/full rw, /dev/zero rw, /dev/random r, /dev/urandom r, capability sys_ptrace, capability sys_admin, # This allows us to read and bind mount the namespace file / r, @{PROC}/ r, @{PROC}/*/ r, @{PROC}/*/ns/ r, @{PROC}/*/ns/mnt r, /run/ r, /run/snapd/ r, /run/snapd/ns/ r, /run/snapd/ns/*.mnt rw, # NOTE: the source name is / even though we map /proc/123/ns/mnt mount options=(rw bind) / -> /run/snapd/ns/*.mnt, # This is the SIGALRM that we send and receive if a timeout expires signal (send, receive) set=(alrm) peer=/snap/core/5897/usr/lib/snapd/snap-confine//mount-namespace-capture-helper, # Those two rules are exactly the same but we don't know if the parent process is still alive # and hence has the appropriate label or is already dead and hence has no label. signal (send) set=(exists) peer=/snap/core/5897/usr/lib/snapd/snap-confine, signal (send) set=(exists) peer=unconfined, # This is so that we can abort signal (send, receive) set=(abrt) peer=/snap/core/5897/usr/lib/snapd/snap-confine//mount-namespace-capture-helper, # This is the signal we get if snap-confine dies (we subscribe to it with prctl) signal (receive) set=(int) peer=/snap/core/5897/usr/lib/snapd/snap-confine, # This allows snap-confine to be killed from the outside. signal (receive) peer=unconfined, # This allows snap-confine to wait for us ptrace (read, trace, tracedby) peer=/snap/core/5897/usr/lib/snapd/snap-confine, } # Allow snap-confine to be killed signal (receive) peer=unconfined, # Allow switching to snap-update-ns with a per-snap profile. change_profile -> snap-update-ns.*, # Allow executing snap-update-ns when... # ...snap-confine is, conceptually, re-executing and uses snap-update-ns # from the distribution package. This is also the location used when using # the core/base snap on all-snap systems. The variants here represent # various locations of libexecdir across distributions. /usr/lib{,exec,64}/snapd/snap-update-ns r, # ...snap-confine is not, conceptually, re-executing and uses # snap-update-ns from the distribution package but we are already inside # the constructed mount namespace so we must traverse "hostfs". The # variants here represent various locations of libexecdir across # distributions. /var/lib/snapd/hostfs/usr/lib{,exec,64}/snapd/snap-update-ns r, # ..snap-confine is, conceptually, re-executing and uses snap-update-ns # from the core snap. Note that the location of the core snap varies from # distribution to distribution. The variants here represent different # locations of snap mount directory across distributions. /{,var/lib/snapd/}snap/core/*/usr/lib/snapd/snap-update-ns r, # ...snap-confine is, conceptually, re-executing and uses snap-update-ns # from the core snap but we are already inside the constructed mount # namespace. Here the apparmor kernel module re-constructs the path to # snap-update-ns using the "hostfs" mount entry rather than the more # "natural" /snap mount entry but we have no control over that. This is # reported as (LP: #1716339). The variants here represent different # locations of snap mount directory across distributions. /var/lib/snapd/hostfs/{,var/lib/snapd/}snap/core/*/usr/lib/snapd/snap-update-ns r, }