fix: bind correct apparmor feature for validating snap seed

During Realtime kernel image build, there was an error during
validating snap seed which derivative images copied 5.19
apparmor feature and can't validate when Realtime kernel (5.15)
installed [0].

To prevent this, bind correct apparmor feature with kernel
version.

[0] https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/2024639

live-build/apparmor/5.19/capability

@@ -0,0 +1 @@
+0xffffff

live-build/apparmor/5.19/caps/mask

@@ -0,0 +1 @@
+chown dac_override dac_read_search fowner fsetid kill setgid setuid setpcap linux_immutable net_bind_service net_broadcast net_admin net_raw ipc_lock ipc_owner sys_module sys_rawio sys_chroot sys_ptrace sys_pacct sys_admin sys_boot sys_nice sys_resource sys_time sys_tty_config mknod lease audit_write audit_control setfcap mac_override mac_admin syslog wake_alarm block_suspend audit_read

live-build/apparmor/5.19/dbus/mask

@@ -0,0 +1 @@
+acquire send receive

live-build/apparmor/5.19/domain/attach_conditions/xattr

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/change_hat

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/change_hatv

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/change_onexec

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/change_profile

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/computed_longest_left

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/fix_binfmt_elf_mmap

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/post_nnp_subset

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/stack

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/domain/version

@@ -0,0 +1 @@
+1.2

live-build/apparmor/5.19/file/mask

@@ -0,0 +1 @@
+create read write exec append mmap_exec link lock

live-build/apparmor/5.19/mount/mask

@@ -0,0 +1 @@
+mount umount pivot_root

live-build/apparmor/5.19/namespaces/pivot_root

@@ -0,0 +1 @@
+no

live-build/apparmor/5.19/namespaces/profile

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/network/af_mask

@@ -0,0 +1 @@
+unspec unix inet ax25 ipx appletalk netrom bridge atmpvc x25 inet6 rose netbeui security key netlink packet ash econet atmsvc rds sna irda pppox wanpipe llc ib mpls can tipc bluetooth iucv rxrpc isdn phonet ieee802154 caif alg nfc vsock kcm qipcrtr smc xdp

live-build/apparmor/5.19/network/af_unix

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/network_v8/af_mask

@@ -0,0 +1 @@
+unspec unix inet ax25 ipx appletalk netrom bridge atmpvc x25 inet6 rose netbeui security key netlink packet ash econet atmsvc rds sna irda pppox wanpipe llc ib mpls can tipc bluetooth iucv rxrpc isdn phonet ieee802154 caif alg nfc vsock kcm qipcrtr smc xdp

live-build/apparmor/5.19/policy/set_load

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/policy/versions/v5

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/policy/versions/v6

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/policy/versions/v7

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/policy/versions/v8

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/ptrace/mask

@@ -0,0 +1 @@
+read trace

live-build/apparmor/5.19/query/label/data

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/query/label/multi_transaction

@@ -0,0 +1 @@
+yes

live-build/apparmor/5.19/query/label/perms

@@ -0,0 +1 @@
+allow deny audit quiet

live-build/apparmor/5.19/rlimit/mask

@@ -0,0 +1 @@
+cpu fsize data stack core rss nproc nofile memlock as locks sigpending msgqueue nice rtprio rttime

live-build/apparmor/5.19/signal/mask

@@ -0,0 +1 @@
+hup int quit ill trap abrt bus fpe kill usr1 segv usr2 pipe alrm term stkflt chld cont stop stp ttin ttou urg xcpu xfsz vtalrm prof winch io pwr sys emt lost

live-build/functions

@@ -767,7 +767,10 @@ snap_validate_seed() {
             # a snap pre-seeding issue can occur, where the incorrect apparmor features are reported
             # basic copy of a directory structure overriding the "generic" feature set
             # which is tied to the LTS kernel
-            cp -R --verbose /usr/share/livecd-rootfs/live-build/apparmor/${kern_major_min}/* /usr/share/livecd-rootfs/live-build/apparmor/generic/
+
+            # Bind kernel apparmor directory to feature directory for snap preseeding
+            umount "${CHROOT_ROOT}/sys/kernel/security/apparmor/features/"
+            mount --bind /usr/share/livecd-rootfs/live-build/apparmor/${kern_major_min} "${CHROOT_ROOT}/sys/kernel/security/apparmor/features/"
         fi
     fi
 
@@ -777,6 +780,14 @@ snap_validate_seed() {
         /usr/lib/snapd/snap-preseed $(realpath "${CHROOT_ROOT}")
         chroot "${CHROOT_ROOT}" apparmor_parser --skip-read-cache --write-cache --skip-kernel-load --verbose  -j `nproc` /etc/apparmor.d
     fi
+
+    # Unmount kernel specific apparmor feature
+    # mount generic apparmor feature again (cleanup)
+    if [ -d /build/config/hooks.d/extra/apparmor/${kern_major_min} ]; then
+        umount "${CHROOT_ROOT}/sys/kernel/security/apparmor/features/"
+        mount -o bind /usr/share/livecd-rootfs/live-build/apparmor/generic "${CHROOT_ROOT}/sys/kernel/security/apparmor/features/"
+    fi
+
 }
 
 snap_from_seed() {