[PATCH net v2 0/2] af_unix: Fix scm_stat.nr_fds leak in unix_dgram_disconnected()

[Siddharth Chintamaneni <sidchintamaneni@gmail.com>]

This series fixes a u->scm_stat.nr_fds accounting leak in
unix_dgram_disconnected() when purging queued skbs from
sk->sk_receive_queue on disconnect, along with a selftest:

- Patch 1 splices sk->sk_receive_queue onto a local list in
  unix_dgram_disconnected() and calls scm_stat_del() before freeing each
  purged skb.
- Patch 2 adds dgram_disconnect_fdinfo to scm_rights.c verifying scm_fds
  in /proc/self/fdinfo/<fd> across connect(AF_UNSPEC) and dead-peer
  send() disconnects.

Changes in v2:
- Drop MSG_OOB patches and tests per Kuniyuki Iwashima.
- Splice sk->sk_receive_queue onto a local list under the queue lock
  before freeing skbs so concurrent senders cannot extend the drain loop.
- Make dgram_disconnect_fdinfo a standalone TEST() instead of running
  no-op fixture variants, and also test dead-peer send() disconnect.
- Link to v1: https://lore.kernel.org/all/20261106051905.218638-1-sidchintamaneni@gmail.com/

Siddharth Chintamaneni (2):
  af_unix: Fix scm_stat.nr_fds leak in unix_dgram_disconnected().
  selftest: af_unix: Test scm_fds on dgram disconnect.

 net/unix/af_unix.c                            | 59 ++++++++------
 .../selftests/net/af_unix/scm_rights.c        | 79 +++++++++++++++++++
 2 files changed, 114 insertions(+), 24 deletions(-)

-- 
2.43.0