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.
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b799207e1e1816b09e7a5920fbb2d5fcf6edd681
access.redhat.com/errata/RHSA-2019:0512
access.redhat.com/errata/RHSA-2019:0514
bugs.chromium.org/p/project-zero/issues/detail?id=1686
cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.75
cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.13
github.com/torvalds/linux/commit/b799207e1e1816b09e7a5920fbb2d5fcf6edd681
support.f5.com/csp/article/K38456756
usn.ubuntu.com/3832-1/
usn.ubuntu.com/3835-1/
usn.ubuntu.com/3847-1/
usn.ubuntu.com/3847-2/
usn.ubuntu.com/3847-3/