Revisit cgroup v2 memory leak patch. LP #1886668

[Allan Grue Soeby]

Hi,

A cgroup v2 memory leak patch was introduced with 5.4.0-40, but reverted 
with 5.4.0-42 due to avoid kernel crash (LP  #1886668).


This as per "SAUCE: Revert "netprio_cgroup: Fix unlimited memory leak of 
v2 cgroups" mentioned in 
https://lists.ubuntu.com/archives/kernel-team/2020-July/111893.html


Meanwhile, the original reason for the crash seems to have been fixed 
upstream with these:

   cgroup: fix cgroup_sk_alloc() for sk_clone_lock() -  Upstream commit 
ad0f75e5f57ccbceec13274e1e242f2b5a6397e

   group: Fix sock_cgroup_data on big-endian - Upstream commit 
14b032b8f8fce03a546dcf365454bec8c4a58d7d


It seems those crash fixes are already in the code base with upstream 
LTS 5.4.53.


Would you consider revisiting this issue, to get the cgroup v2 memleak 
fix back in place ?


Best regards,

Allan Grue Soeby