Re: [PATCH net] mac802154: wait for RCU readers when removing interfaces
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-06-30 21:47:39
Also in:
lkml, stable
From: Yousef Alhouseen <redacted> Date: Tue, 30 Jun 2026 23:18:08 +0200
Queue wake, stop, and disable paths walk local->interfaces under RCU. The bulk hardware teardown path removes entries with list_del() and
The problematic part is list_del(), not unregister_netdevice().
immediately unregisters their netdevices, so an asynchronous transmit
not immediately, unregister_netdevice() waits inflight RCU readers. So, synchronize_rcu() should be unnecessary. (Same remark for ieee802154_if_remove())
quoted hunk ↗ jump to hunk
completion can follow a poisoned list node in ieee802154_wake_queue(). Match ieee802154_if_remove(): use list_del_rcu() and wait for existing readers before unregistering each interface. Fixes: 592dfbfc72f5 ("mac820154: move interface unregistration into iface") Reported-by: syzbot+36256deb69a588e9290e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=36256deb69a588e9290e Cc: stable@vger.kernel.org Signed-off-by: Yousef Alhouseen <redacted> --- net/mac802154/iface.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c index 000be60d9580..73d82a015184 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c@@ -703,7 +703,8 @@ void ieee802154_remove_interfaces(struct ieee802154_local *local) mutex_lock(&local->iflist_mtx); list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) { - list_del(&sdata->list); + list_del_rcu(&sdata->list); + synchronize_rcu(); unregister_netdevice(sdata->dev); }--