This is a note to let you know that I've just added the patch titled mac80211: mlme: find auth challenge directly to the 5.4-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: mac80211-mlme-find-auth-challenge-directly.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Oct 15 05:24:51 PM CEST 2022 From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Date: Fri, 14 Oct 2022 18:47:03 +0200 Subject: mac80211: mlme: find auth challenge directly To: linux-wireless@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx Cc: Felix Fietkau <nbd@xxxxxxxx>, Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>, Marcus Meissner <meissner@xxxxxxx>, Jiri Kosina <jkosina@xxxxxxx>, Steve deRosier <steve.derosier@xxxxxxxxx>, Johannes Berg <johannes.berg@xxxxxxxxx> Message-ID: <20221014164705.31486-2-johannes@xxxxxxxxxxxxxxxx> From: Johannes Berg <johannes.berg@xxxxxxxxx> There's no need to parse all elements etc. just to find the authentication challenge - use cfg80211_find_elem() instead. This also allows us to remove WLAN_EID_CHALLENGE handling from the element parsing entirely. Link: https://lore.kernel.org/r/20210920154009.45f9b3a15722.Ice3159ffad03a007d6154cbf1fb3a8c48489e86f@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/ieee80211_i.h | 2 -- net/mac80211/mlme.c | 11 ++++++----- net/mac80211/util.c | 4 ---- 3 files changed, 6 insertions(+), 11 deletions(-) --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1460,7 +1460,6 @@ struct ieee802_11_elems { const u8 *supp_rates; const u8 *ds_params; const struct ieee80211_tim_ie *tim; - const u8 *challenge; const u8 *rsn; const u8 *erp_info; const u8 *ext_supp_rates; @@ -1507,7 +1506,6 @@ struct ieee802_11_elems { u8 ssid_len; u8 supp_rates_len; u8 tim_len; - u8 challenge_len; u8 rsn_len; u8 ext_supp_rates_len; u8 wmm_info_len; --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2829,14 +2829,14 @@ static void ieee80211_auth_challenge(str { struct ieee80211_local *local = sdata->local; struct ieee80211_mgd_auth_data *auth_data = sdata->u.mgd.auth_data; + const struct element *challenge; u8 *pos; - struct ieee802_11_elems elems; u32 tx_flags = 0; pos = mgmt->u.auth.variable; - ieee802_11_parse_elems(pos, len - (pos - (u8 *)mgmt), false, &elems, - mgmt->bssid, auth_data->bss->bssid); - if (!elems.challenge) + challenge = cfg80211_find_elem(WLAN_EID_CHALLENGE, pos, + len - (pos - (u8 *)mgmt)); + if (!challenge) return; auth_data->expected_transaction = 4; drv_mgd_prepare_tx(sdata->local, sdata, 0); @@ -2844,7 +2844,8 @@ static void ieee80211_auth_challenge(str tx_flags = IEEE80211_TX_CTL_REQ_TX_STATUS | IEEE80211_TX_INTFL_MLME_CONN_TX; ieee80211_send_auth(sdata, 3, auth_data->algorithm, 0, - elems.challenge - 2, elems.challenge_len + 2, + (void *)challenge, + challenge->datalen + sizeof(*challenge), auth_data->bss->bssid, auth_data->bss->bssid, auth_data->key, auth_data->key_len, auth_data->key_idx, tx_flags); --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1006,10 +1006,6 @@ _ieee802_11_parse_elems_crc(const u8 *st } else elem_parse_failed = true; break; - case WLAN_EID_CHALLENGE: - elems->challenge = pos; - elems->challenge_len = elen; - break; case WLAN_EID_VENDOR_SPECIFIC: if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 && pos[2] == 0xf2) { Patches currently in stable-queue which might be from johannes@xxxxxxxxxxxxxxxx are queue-5.4/wifi-mac80211-don-t-parse-mbssid-in-assoc-response.patch queue-5.4/mac80211-mlme-find-auth-challenge-directly.patch queue-5.4/wifi-mac80211-fix-mbssid-parsing-use-after-free.patch