I'm going to assume that there was "old" code that caused LPE vulnerabilities, but, The Linux Foundation have their own project Sashiko (https://sashiko.dev/), which analyzes each commit to the Linux Kernel for bugs and vulnerabilities using Googles models, my question is then, how many of the vulnerabilities you found were also caught by Sashiko?
If Sashiko had found them then they wouldn't have been merged, so my guess is 0