[PATCH 4.14 0/4] BPF fixes for CVE-2021-3444 and CVE-2021-3600

[Thadeu Lima de Souza Cascardo <cascardo@canonical.com>]

The upstream changes necessary to fix these CVEs rely on the presence of JMP32,
which is not a small backport and brings its own potential set of necessary
follow-ups.

Daniel Borkmann, John Fastabend and Alexei Starovoitov came up with a fix
involving the use of the AX register.

This has been tested against the test_verifier in 4.14.y tree and some tests
specific to the two referred CVEs. The test_bpf module was also tested.

Daniel Borkmann (4):
  bpf: Do not use ax register in interpreter on div/mod
  bpf: fix subprog verifier bypass by div/mod by 0 exception
  bpf: Fix 32 bit src register truncation on div/mod
  bpf: Fix truncation handling for mod32 dst reg wrt zero

 include/linux/filter.h | 24 ++++++++++++++++++++++++
 kernel/bpf/core.c      | 40 +++++++++++++++-------------------------
 kernel/bpf/verifier.c  | 39 +++++++++++++++++++++++++++++++--------
 net/core/filter.c      |  9 ++++++++-
 4 files changed, 78 insertions(+), 34 deletions(-)

-- 
2.30.2