[PATCH v2 0/4] Fix unsafe BPF_PROG_TEST_RUN interface

[Lorenz Bauer <lmb@cloudflare.com>]

Right now, there is no safe way to use BPF_PROG_TEST_RUN with data_out.
This is because bpf_test_finish copies the output buffer to user space
without checking its size. This can lead to the kernel overwriting
data in user space after the buffer if xdp_adjust_head and friends are
in play.

Changes in v2:
* Make the syscall return ENOSPC if data_size_out is too small
* Make bpf_prog_test_run return EINVAL if size_out is missing
* Document the new behaviour of data_size_out

Lorenz Bauer (4):
  bpf: respect size hint to BPF_PROG_TEST_RUN if present
  tools: sync uapi/linux/bpf.h
  libbpf: require size hint in bpf_prog_test_run
  selftests: add a test for bpf_prog_test_run output size

 include/uapi/linux/bpf.h                 |  7 ++--
 net/bpf/test_run.c                       | 15 ++++++--
 tools/include/uapi/linux/bpf.h           |  7 ++--
 tools/lib/bpf/bpf.c                      |  7 +++-
 tools/testing/selftests/bpf/test_progs.c | 44 ++++++++++++++++++++++++
 5 files changed, 73 insertions(+), 7 deletions(-)

-- 
2.17.1