APPLIED[Unstable]: [SRU D/E/F/G/U 0/1] Revert code that causes crashes on default configurations

[seth.forshee at canonical.com]

On Thu, Jul 09, 2020 at 04:54:00PM -0300, Thadeu Lima de Souza Cascardo wrote:
> BugLink: https://bugs.launchpad.net/bugs/1886668
> 
> This is the same patch as sent to Bionic 4.15 kernels.
> 
> [Impact]
> On systems using cgroups and sockets extensively, like docker, kubernetes,
> lxd, libvirt, a crash might happen when using linux 4.15.0-109-generic.
> 
> [Fix]
> Revert the patch that disables sk_alloc cgroup refcounting when tasks
> are added to net_prio cgroup.
> 
> [Test case]
> Test that such environments where the issue is reproduced survive some hours of
> uptime. A different bug was reproduced with a work-in-progress code and was not
> reproduced with the culprit reverted.
> 
> [Regression potential]
> The reverted commit fix a memory leak on similar scenarios. But a leak is
> better than a crash. Two other bugs have been opened to track a real fix for
> this issue and the leak.

Applied to unstable, thanks!