Funny that blog calls it a "failed attempt at a backdoor" while neglecting to mention that the grsec post (which it does link to and acknowledges is the source of the story) had been updated months prior to explicitly refute that characterization:

5/22/2020 Update: This kind of update should not have been necessary, but due to irresponsible journalists and the nature of social media, it is important to make some things perfectly clear:

Nowhere did we claim this was anything more than a trivially exploitable vulnerability. It is not a backdoor or an attempted backdoor, the term does not appear elsewhere in this blog at all; any suggestion of the sort was fabricated by irresponsible journalists who did not contact us and do not speak for us.

There is no chance this code would have passed review and be merged. No one can push or force code upstream.

This code is not characteristic of the quality of other code contributed upstream by Huawei. Contrary to baseless assertions from some journalists, this is not Huawei's first attempt at contributing to the kernel, in fact they've been a frequent contributor for some time.

selinux is one example.