From 78a6a43aaf87180ec7425a2a90468e1b4d09a1ec Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 21 Sep 2022 02:44:58 +0200 Subject: wifi: mac80211: mlme: fix null-ptr deref on failed assoc If association to an AP without a link 0 fails, then we crash in tracing because it assumes that either ap_mld_addr or link 0 BSS is valid, since we clear sdata->vif.valid_links and then don't add the ap_mld_addr to the struct. Since we clear also sdata->vif.cfg.ap_addr, keep a local copy of it and assign it earlier, before clearing valid_links, to fix this. Fixes: 81151ce462e5 ("wifi: mac80211: support MLO authentication/association with one link") Signed-off-by: Johannes Berg --- net/mac80211/mlme.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/mac80211/mlme.c') diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index b6f378e7edea..1ad0bf3bfcae 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -5082,6 +5082,7 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata, struct cfg80211_rx_assoc_resp resp = { .uapsd_queues = -1, }; + u8 ap_mld_addr[ETH_ALEN] __aligned(2); unsigned int link_id; sdata_assert_lock(sdata); @@ -5251,6 +5252,11 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata, resp.uapsd_queues |= ieee80211_ac_to_qos_mask[ac]; } + if (sdata->vif.valid_links) { + ether_addr_copy(ap_mld_addr, sdata->vif.cfg.ap_addr); + resp.ap_mld_addr = ap_mld_addr; + } + ieee80211_destroy_assoc_data(sdata, status_code == WLAN_STATUS_SUCCESS ? ASSOC_SUCCESS : @@ -5260,8 +5266,6 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata, resp.len = len; resp.req_ies = ifmgd->assoc_req_ies; resp.req_ies_len = ifmgd->assoc_req_ies_len; - if (sdata->vif.valid_links) - resp.ap_mld_addr = sdata->vif.cfg.ap_addr; cfg80211_rx_assoc_resp(sdata->dev, &resp); notify_driver: drv_mgd_complete_tx(sdata->local, sdata, &info); -- cgit