Citation needed :)
Seriously, all software has bugs, how do you judge the quality of an operating system that is not finished?
Does Google itself help?
https://events19.linuxfoundation.org/wp-content/uploads/2017...
https://outflux.net/slides/2019/lss/kspp.pdf
Slides from 2018 and 2019 talks.
Linux is full of security bugs. It is ludicrous to suggest Linux is high quality. OpenBSD, maybe. Not Linux.