From b34c2340657cfe467a0c2cde4933422bddf4348b Mon Sep 17 00:00:00 2001
From: Alexey Tikhonov <atikhono@redhat.com>
Date: Wed, 20 Dec 2023 18:28:34 +0100
Subject: unix.7: SO_PEERCRED: Mention listen(2)

In case of connected AF_UNIX stream sockets, server-side credentials are
set at the time of a call to listen(2), not when client-side calls
connect(2).

This is important if server side process changes UID/GID after listen(2)
and before connect(2).

Reproducer is available in [1].
Behavior was confirmed in the email thread [2].

Link: [1] <https://bugzilla.redhat.com/show_bug.cgi?id=2247682>
Link: [2] <https://lore.kernel.org/linux-man/CABPeg3a9L0142gmdZZ+0hoD+Q3Vgv0BQ21g8Z+gf2kznWouErA@mail.gmail.com/>
Signed-off-by: Alexey Tikhonov <atikhono@redhat.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
---
 man7/unix.7 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/man7/unix.7 b/man7/unix.7
index e9edad467..71cdfc758 100644
--- a/man7/unix.7
+++ b/man7/unix.7
@@ -331,7 +331,8 @@ This read-only socket option returns the
 credentials of the peer process connected to this socket.
 The returned credentials are those that were in effect at the time
 of the call to
-.BR connect (2)
+.BR connect (2),
+.BR listen (2),
 or
 .BR socketpair (2).
 .IP
-- 
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