In the Linux kernel 4.14.x, 4.15.x, 4.16.x, 4.17.x, and 4.18.x before 4.18.13, faulty computation of numeric bounds in the BPF verifier permits out-of-bounds memory accesses because adjust_scalar_min_max_vals in kernel/bpf/verifier.c mishandles 32-bit right shifts.