On Tue, Jul 07, 2026 at 01:30:39PM +0900, Yuyang Huang wrote:

quoted

To prevent RCU readers from accessing a partially destroyed in_device,
clear dev->ip_ptr early in inetdev_destroy() before freeing the
multicast list and individual IP addresses. This aligns the IPv4 teardown
sequence with the IPv6 implementation.

Cc: Ido Schimmel <idosch@nvidia.com>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Signed-off-by: Yuyang Huang <redacted>

I believe that sashiko-gemini [1] is right and you need to teach
prestera to ignore NETDEV_DOWN notifications in the inetaddr chain when
a RIF doesn't exist. Something like [2].

Regarding ieee80211_ifa_changed(), the net device is being tore down, so
failing to update the firmware ARP filter probably doesn't matter, but
you can do something like [3] to avoid it completely.

So, three patches where the last one aligns IPv4 with IPv6. Please check
if other listeners need to be adjusted (mlxsw is OK).

Thanks

[1] https://sashiko.dev/#/patchset/20260707043039.101983-1-yuyanghuang%40google.com

[2]

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_router.c b/drivers/net/ethernet/marvell/prestera/prestera_router.c
index b036b173a308..0c4f462baa6e 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_router.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_router.c

@@ -1302,10 +1302,8 @@ static int __prestera_inetaddr_port_event(struct net_device *port_dev,
                dev_hold(port_dev);
                break;
        case NETDEV_DOWN:
-               if (!re) {
-                       NL_SET_ERR_MSG_MOD(extack, "Can't find RIF");
-                       return -EEXIST;
-               }
+               if (!re)
+                       return 0;
                prestera_rif_entry_destroy(port->sw, re);
                dev_put(port_dev);
                break;

[3]

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 90d295cc364f..0e7a60dd1d8d 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c

@@ -588,9 +588,7 @@ static int ieee80211_ifa_changed(struct notifier_block *nb,
        if (sdata->vif.type != NL80211_IFTYPE_STATION)
                return NOTIFY_DONE;

-       idev = __in_dev_get_rtnl(sdata->dev);
-       if (!idev)
-               return NOTIFY_DONE;
+       idev = ifa->ifa_dev;

        ifmgd = &sdata->u.mgd;