[PATCH bpf-next 0/6] bpf: handle another corner case in getsockopt

[Stanislav Fomichev <sdf@xxxxxxxxxx>]

Martin reports another case where getsockopt EFAULTs perfectly
valid callers. Let's fix it and also replace EFAULT with
pr_info_ratelimited. That should hopefully make this place
less error prone.

First 2 patches fix the issue with NETLINK_LIST_MEMBERSHIPS and
test it.

Second 2 patches replace EFAULT with pr_inro_limited and update
the tests.

The remaining patches update documentation and existing selftests
to be more gentle with 'optlen > 4096' cases. People might be
copy-pasting from there, so let's be more pedantic.

Cc: Martin KaFai Lau <martin.lau@xxxxxxxxxx>

Stanislav Fomichev (6):
  bpf: Don't EFAULT for getsockopt with optval=NULL
  selftests/bpf: Verify optval=NULL case
  bpf: Don't EFAULT for {g,s}setsockopt with wrong optlen
  selftests/bpf: Update EFAULT {g,s}etsockopt selftests
  selftests/bpf: Correctly handle optlen > 4096
  bpf: Document EFAULT changes for sockopt

 Documentation/bpf/prog_cgroup_sockopt.rst     | 64 +++++++++++++++++--
 kernel/bpf/cgroup.c                           | 17 +++--
 .../selftests/bpf/prog_tests/sockopt.c        | 42 ++++--------
 .../selftests/bpf/prog_tests/sockopt_sk.c     | 28 ++++++++
 .../progs/cgroup_getset_retval_getsockopt.c   | 12 ++++
 .../progs/cgroup_getset_retval_setsockopt.c   | 16 +++++
 .../selftests/bpf/progs/sockopt_inherit.c     | 16 ++++-
 .../selftests/bpf/progs/sockopt_multi.c       | 24 ++++++-
 .../selftests/bpf/progs/sockopt_qos_to_cc.c   |  8 ++-
 .../testing/selftests/bpf/progs/sockopt_sk.c  | 33 ++++++++--
 10 files changed, 211 insertions(+), 49 deletions(-)

-- 
2.40.0.634.g4ca3ef3211-goog