Fix for UDP sockets getting leaked during sockmap lookup/release.
Accompanied by selftests updates.

Two Sashiko's concerns to be addressed separately:
https://lore.kernel.org/bpf/20260626205814.BAC3C1F000E9@smtp.kernel.org/ (local)

Signed-off-by: Michal Luczaj <redacted>
---
Changes in v3:
- selftest: better error handling, ASSERT_*() macros [Sashiko]
- selftest: fix grammar, reorder patches [Kuniyuki]
- Link to v2: https://patch.msgid.link/20260626-sockmap-lookup-udp-leak-v2-0-7e7e201c951a@rbox.co

Changes in v2:
- selftest: drop the original, adapt old tests
- fix: change approach to rejecting unbound UDP [Kuniyuki]
- Link to v1: https://patch.msgid.link/20260623-sockmap-lookup-udp-leak-v1-0-05804f9308e4@rbox.co

To: Alexei Starovoitov <ast@kernel.org>
To: Daniel Borkmann <daniel@iogearbox.net>
To: Andrii Nakryiko <andrii@kernel.org>
To: Eduard Zingerman <eddyz87@gmail.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: Martin KaFai Lau <martin.lau@linux.dev>
To: Song Liu <song@kernel.org>
To: Yonghong Song <yonghong.song@linux.dev>
To: Jiri Olsa <jolsa@kernel.org>
To: Emil Tsalapatis <emil@etsalapatis.com>
To: Shuah Khan <shuah@kernel.org>
To: John Fastabend <john.fastabend@gmail.com>
To: Jakub Sitnicki <jakub@cloudflare.com>
To: Jiayuan Chen <jiayuan.chen@linux.dev>
To: Eric Dumazet <edumazet@google.com>
To: Kuniyuki Iwashima <kuniyu@google.com>
To: Paolo Abeni <pabeni@redhat.com>
To: Willem de Bruijn <willemb@google.com>
To: "David S. Miller" <davem@davemloft.net>
To: Jakub Kicinski <kuba@kernel.org>
To: Simon Horman <horms@kernel.org>
To: Cong Wang <redacted>
Cc: bpf@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org

---
Michal Luczaj (4):
      selftests/bpf: Ensure UDP sockets are bound
      bpf, sockmap: Reject unhashed UDP sockets on sockmap update
      selftests/bpf: Adapt sockmap update error handling
      selftests/bpf: Fail unbound UDP on sockmap update

 net/core/sock_map.c                                 |  2 ++
 .../selftests/bpf/prog_tests/sockmap_basic.c        |  6 +++---
 .../selftests/bpf/prog_tests/sockmap_listen.c       | 21 +++++++++++----------
 tools/testing/selftests/bpf/test_maps.c             | 13 ++++++-------
 4 files changed, 22 insertions(+), 20 deletions(-)
---
base-commit: c341792c9c7272cf91c8b17eae929caed7c2a732
change-id: 20260617-sockmap-lookup-udp-leak-bc4e5c5481d7

Best regards,
--  
Michal Luczaj [off-list ref]