The do_check function in kernel/bpf/verifier.c in the Linux kernel before 4.11.1 does not make the allow_ptr_leaks value available for restricting the output of the print_bpf_insn function, which allows local users to obtain sensitive address information via crafted bpf system calls.
https://www.exploit-db.com/exploits/42048/
https://source.android.com/security/bulletin/2017-09-01
https://github.com/torvalds/linux/commit/0d0e57697f162da4aa218b5feafe614fb666db07
https://bugs.chromium.org/p/project-zero/issues/detail?id=1251
http://www.securityfocus.com/bid/98635
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.11.1