Comment 0 for bug 1939915

There's a memory leak in the kernel when removing a profile.
A simple reproducible example:

root@ubuntu:~# echo "profile foo {}" > profile
root@ubuntu:~# apparmor_parser profile
root@ubuntu:~# echo scan > /sys/kernel/debug/kmemleak
root@ubuntu:~# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff99bcf5128bb0 (size 16):
  comm "apparmor_parser", pid 1318, jiffies 4295139856 (age 33.196s)
  hex dump (first 16 bytes):
    01 00 00 00 00 00 00 00 98 1f 01 fd bc 99 ff ff ................
  backtrace:
    [<00000000b1f68969>] kmem_cache_alloc_trace+0xd8/0x1e0
    [<0000000086ca7bd9>] aa_alloc_proxy+0x30/0x60
    [<000000000e34f34c>] aa_alloc_profile+0xd4/0x100
    [<00000000c2e34769>] unpack_profile+0x16f/0xe10
    [<0000000019033e2b>] aa_unpack+0x119/0x500
    [<00000000a97520b2>] aa_replace_profiles+0x94/0xca0
    [<000000001833f520>] policy_update+0x124/0x1e0
    [<00000000992f950e>] profile_load+0x7d/0xa0
    [<00000000db7852ce>] __vfs_write+0x1b/0x40
    [<000000004e709f5d>] vfs_write+0xb9/0x1a0
    [<00000000280db840>] SyS_write+0x5e/0xe0
    [<0000000014c5ab5d>] do_syscall_64+0x79/0x130
    [<00000000e962a389>] entry_SYSCALL_64_after_hwframe+0x41/0xa6
    [<000000009d368497>] 0xffffffffffffffff

This issue was already fixed upstream 3622ad25d4d6 v5.8-rc1~102^2
It still needs to be applied on xenial, bionic and focal.