kernel/bpf/verifier.c in the Linux kernel through 4.14.8 ignores unreachable code, even though it would still be processed by JIT compilers. This behavior, also considered an improper branch-pruning logic issue, could possibly be used by local users for denial of service.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c131187db2d3fa2f8bf32fdf4e9a4ef805168467
www.securityfocus.com/bid/102325
www.securitytracker.com/id/1040057
anonscm.debian.org/cgit/kernel/linux.git/tree/debian/patches/bugfix/all/bpf-fix-branch-pruning-logic.patch?h=stretch-security
github.com/torvalds/linux/commit/c131187db2d3fa2f8bf32fdf4e9a4ef805168467
usn.ubuntu.com/3619-1/
usn.ubuntu.com/3619-2/
usn.ubuntu.com/usn/usn-3523-2/
www.debian.org/security/2017/dsa-4073
www.spinics.net/lists/stable/msg206984.html