Comment 8 for bug 1883962

Verification done on Eoan.
The apparmor label refcnt inc/dec-rements properly on accept()/release(), no leaks.

$ lsb_release -cs
eoan

$ uname -rv
5.3.0-63-generic #57-Ubuntu SMP Thu Jul 2 10:38:35 UTC 2020

$ apt-cache policy linux-image-$(uname -r)
linux-image-5.3.0-63-generic:
...
 *** 5.3.0-63.57 500
        500 http://archive.ubuntu.com/ubuntu eoan-proposed/main amd64 Packages
...

$ gcc -o aa-refcnt-af_alg aa-refcnt-af_alg.c
$ ./aa-refcnt-af_alg &

$ make
$ sudo insmod kmod.ko &

$ dmesg
...
[ 254.940413] accept() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a4
[ 254.941665] release() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a5
[ 254.942932] accept() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a4
[ 254.944187] release() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a5
[ 254.945484] accept() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a4
[ 254.946741] release() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a5
[ 254.948023] accept() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a4
[ 254.949282] release() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a5
[ 254.950572] accept() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a4
[ 254.952526] release() :: comm = aa-refcnt-af_al, pid = 1540, sk->sk_security->label->count = 0x6a5
...

$ sudo rmmod kmod