From: Johannes Berg <johannes.berg@intel.com> mainline inclusion from mainline-v7.3-rc4 commit eee2efd82867b623982ac51925b5a1812a74c50d category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/20061 CVE: CVE-2026-98331 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- mac80211 only removes vifs from the local->interfaces list when an interface is removed via ieee80211_if_remove(), before it unregisters the netdev. However, it's possible for a netdev to be unregistered without going through that: When the netns that holds the wiphy is destroyed, the wiphy is supposed to move to the init_ns, but that can run into allocation failures. Then, mac80211 has an interface listed that doesn't exist, and will eventually hit BUG: failure at net/wireless/core.h:141/wiphy_to_rdev()! ... _cfg80211_unregister_wdev+0x24/0x36a [cfg80211] cfg80211_unregister_wdev+0x15/0x1d [cfg80211] ieee80211_remove_interfaces+0x1ff/0x257 [mac80211] ieee80211_unregister_hw+0x73/0x1d1 [mac80211] mac80211_hwsim_del_radio+0x114/0x166 [mac80211_hwsim] Remove the interface from the list in ->ndo_uninit if it's still around to avoid this. Assisted-by: LLM Fixes: 463d018323851 ("cfg80211: make aware of net namespaces") Link: https://patch.msgid.link/20260904170220.038ad73e6c04.I990abca78483e058746b6f... Signed-off-by: Johannes Berg <johannes.berg@intel.com> Conflicts: net/mac80211/iface.c [Context conflicts. The current branch does not yet support guard(mutex)(&local->iflist_mtx), so mutex_lock is used as an equivalent replacement.] Signed-off-by: Gu Bowen <gubowen5@huawei.com> --- net/mac80211/iface.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 55e3dfa7505d..313d387045d1 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -706,9 +706,34 @@ static void ieee80211_teardown_sdata(struct ieee80211_sub_if_data *sdata) ieee80211_mesh_teardown_sdata(sdata); } +/* + * The netdev can be unregistered without mac80211 doing it, e.g. by the netdev + * core when cfg80211 couldn't move it out of a network namespace that's being + * destroyed. Drop it from the interface list either way. + */ +static void ieee80211_unlist_sdata(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_sub_if_data *iter; + + ASSERT_RTNL(); + + list_for_each_entry(iter, &local->interfaces, list) { + if (iter != sdata) + continue; + mutex_lock(&local->iflist_mtx); + list_del_rcu(&sdata->list); + mutex_unlock(&local->iflist_mtx); + return; + } +} + static void ieee80211_uninit(struct net_device *dev) { - ieee80211_teardown_sdata(IEEE80211_DEV_TO_SUB_IF(dev)); + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + + ieee80211_unlist_sdata(sdata); + ieee80211_teardown_sdata(sdata); } static u16 ieee80211_netdev_select_queue(struct net_device *dev, -- 2.43.0