[bpf,v2,0/2] bpf, fix for subprogs with tailcalls

Message

John Fastabend July 7, 2021, 10:38 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.

v2: original patch missed fixups needed in out label as Daniel caught 

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                         | 45 ++++---------------
 .../selftests/bpf/prog_tests/tailcalls.c      | 36 ++++++++++-----
 .../selftests/bpf/progs/tailcall_bpf2bpf4.c   | 21 ++++++++-
 6 files changed, 65 insertions(+), 49 deletions(-)