kernel/bpf/verifier.c in the Linux kernel 4.9.x through 4.9.71 does not check the relationship between pointer values and the BPF stack, which allows local users to cause a denial of service (integer overflow or invalid memory access) or possibly have unspecified other impact. Jann Horn discovered that the Berkeley Packet Filter (BPF) implementation in the Linux kernel did not properly check the relationship between pointer values and the BPF stack. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.