[bpf,0/2] bpf, fix for subprogs with tailcalls

Message

John Fastabend June 30, 2021, 7:40 p.m. UTC

This fixes a use-after-free when using subprogs and tailcalls and adds
a test case to trigger the use-after-free.

John Fastabend (2):
  bpf: track subprog poke correctly, fix use-after-free
  bpf: selftest to verify mixing bpf2bpf calls and tailcalls with insn
    patch

 arch/x86/net/bpf_jit_comp.c                   |  4 ++
 include/linux/bpf.h                           |  1 +
 kernel/bpf/core.c                             |  7 +++-
 kernel/bpf/verifier.c                         | 39 ++++---------------
 .../selftests/bpf/prog_tests/tailcalls.c      | 36 ++++++++++++-----
 .../selftests/bpf/progs/tailcall_bpf2bpf4.c   | 21 +++++++++-
 6 files changed, 64 insertions(+), 44 deletions(-)