This is a note to let you know that I've just added the patch titled wifi: mac80211: mlme: fix null-ptr deref on failed assoc to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-mac80211-mlme-fix-null-ptr-deref-on-failed-asso.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c7f8032a812f28e98c69c367306e7e8f91d6fb23 Author: Johannes Berg <johannes.berg@xxxxxxxxx> Date: Wed Sep 21 02:44:58 2022 +0200 wifi: mac80211: mlme: fix null-ptr deref on failed assoc [ Upstream commit 78a6a43aaf87180ec7425a2a90468e1b4d09a1ec ] 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 <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 654414caeb71..a21571eb02ec 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -4955,6 +4955,7 @@ 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); @@ -5119,6 +5120,11 @@ 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 : @@ -5128,8 +5134,6 @@ 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);