From: Wei Yongjun <weiyongjun1@xxxxxxxxxx> [ Upstream commit b3d72d3135d2ef68296c1ee174436efd65386f04 ] Kernel fault injection test reports null-ptr-deref as follows: BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:cfg802154_netdev_notifier_call+0x120/0x310 include/linux/list.h:114 Call Trace: <TASK> raw_notifier_call_chain+0x6d/0xa0 kernel/notifier.c:87 call_netdevice_notifiers_info+0x6e/0xc0 net/core/dev.c:1944 unregister_netdevice_many_notify+0x60d/0xcb0 net/core/dev.c:1982 unregister_netdevice_queue+0x154/0x1a0 net/core/dev.c:10879 register_netdevice+0x9a8/0xb90 net/core/dev.c:10083 ieee802154_if_add+0x6ed/0x7e0 net/mac802154/iface.c:659 ieee802154_register_hw+0x29c/0x330 net/mac802154/main.c:229 mcr20a_probe+0xaaa/0xcb1 drivers/net/ieee802154/mcr20a.c:1316 ieee802154_if_add() allocates wpan_dev as netdev's private data, but not init the list in struct wpan_dev. cfg802154_netdev_notifier_call() manage the list when device register/unregister, and may lead to null-ptr-deref. Use INIT_LIST_HEAD() on it to initialize it correctly. Fixes: fcf39e6e88e9 ("ieee802154: add wpan_dev_list") Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx> Acked-by: Alexander Aring <aahringo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221130091705.1831140-1-weiyongjun@xxxxxxxxxxxxxxx Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/mac802154/iface.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c index 06019dba4b10..9f2355cb6701 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c @@ -670,6 +670,7 @@ ieee802154_if_add(struct ieee802154_local *local, const char *name, sdata->dev = ndev; sdata->wpan_dev.wpan_phy = local->hw.phy; sdata->local = local; + INIT_LIST_HEAD(&sdata->wpan_dev.list); /* setup type-dependent data */ ret = ieee802154_setup_sdata(sdata, type); -- 2.35.1