Or in other parts of the kernel. It's been the case in multiple occasions that buggy locking (or more generalised, missing 'resource' release) has caused problems for perfectly safe BPF programs. For example, see
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1033398 and the fix
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...