From 6ee3390c978dca7a590a4c16d4d620984e60fa96 Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Fri, 10 Sep 2021 08:09:56 +0900
Subject: [PATCH] network: fix handling of network interface renaming

Fixes #20657.

(cherry picked from commit 160203e974945ce520fe8f569458634ef898c61c)

Conflict:NA
Reference:https://github.com/systemd/systemd/commit/6ee3390c978dca7a590a4c16d4d620984e60fa96
---
 src/network/networkd-link.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index d58b700050..20675f2306 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1404,17 +1404,21 @@ static int link_initialized(Link *link, sd_device *device) {
         assert(link);
         assert(device);
 
-        if (link->state != LINK_STATE_PENDING)
-                return 0;
+        /* Always replace with the new sd_device object. As the sysname (and possibly other properties
+         * or sysattrs) may be outdated. */
+        sd_device_ref(device);
+        sd_device_unref(link->sd_device);
+        link->sd_device = device;
 
-        if (link->sd_device)
+        /* Do not ignore unamanaged state case here. If an interface is renamed after being once
+         * configured, and the corresponding .network file has Name= in [Match] section, then the
+         * interface may be already in unmanaged state. See #20657. */
+        if (!IN_SET(link->state, LINK_STATE_PENDING, LINK_STATE_UNMANAGED))
                 return 0;
 
         log_link_debug(link, "udev initialized link");
         link_set_state(link, LINK_STATE_INITIALIZED);
 
-        link->sd_device = sd_device_ref(device);
-
         /* udev has initialized the link, but we don't know if we have yet
          * processed the NEWLINK messages with the latest state. Do a GETLINK,
          * when it returns we know that the pending NEWLINKs have already been
-- 
2.33.0

