kernel/bpf/verifier.c in the Linux kernel before 4.20.6 performs undesirable out-of-bounds speculation on pointer arithmetic in various cases, including cases of different branches with different state or limits to sanitize, leading to side-channel attacks.
https://usn.ubuntu.com/3931-2/
https://usn.ubuntu.com/3931-1/
https://usn.ubuntu.com/3930-2/
https://usn.ubuntu.com/3930-1/
https://support.f5.com/csp/article/K43030517?utm_source=f5support&%3Butm_medium=RSS
https://support.f5.com/csp/article/K43030517
https://github.com/torvalds/linux/commit/d3bd7413e0ca40b60cf60d4003246d067cafdeda
https://github.com/torvalds/linux/commit/979d63d50c0c0f7bc537bf821e056cc9fe5abd38
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.6
https://bugs.chromium.org/p/project-zero/issues/detail?id=1711
http://www.securityfocus.com/bid/106827
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00052.html