This is a note to let you know that I've just added the patch titled wifi: cfg80211: Fix use after free for wext to the 6.2-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-cfg80211-fix-use-after-free-for-wext.patch and it can be found in the queue-6.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 015b8cc5e7c4d7bb671f1984d7b7338c310b185b Mon Sep 17 00:00:00 2001 From: Alexander Wetzel <alexander@xxxxxxxxxxxxxx> Date: Tue, 24 Jan 2023 15:18:56 +0100 Subject: wifi: cfg80211: Fix use after free for wext From: Alexander Wetzel <alexander@xxxxxxxxxxxxxx> commit 015b8cc5e7c4d7bb671f1984d7b7338c310b185b upstream. Key information in wext.connect is not reset on (re)connect and can hold data from a previous connection. Reset key data to avoid that drivers or mac80211 incorrectly detect a WEP connection request and access the freed or already reused memory. Additionally optimize cfg80211_sme_connect() and avoid an useless schedule of conn_work. Fixes: fffd0934b939 ("cfg80211: rework key operation") Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20230124141856.356646-1-alexander@xxxxxxxxxxxxxx Signed-off-by: Alexander Wetzel <alexander@xxxxxxxxxxxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/wireless/sme.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -285,6 +285,15 @@ void cfg80211_conn_work(struct work_stru wiphy_unlock(&rdev->wiphy); } +static void cfg80211_step_auth_next(struct cfg80211_conn *conn, + struct cfg80211_bss *bss) +{ + memcpy(conn->bssid, bss->bssid, ETH_ALEN); + conn->params.bssid = conn->bssid; + conn->params.channel = bss->channel; + conn->state = CFG80211_CONN_AUTHENTICATE_NEXT; +} + /* Returned bss is reference counted and must be cleaned up appropriately. */ static struct cfg80211_bss *cfg80211_get_conn_bss(struct wireless_dev *wdev) { @@ -302,10 +311,7 @@ static struct cfg80211_bss *cfg80211_get if (!bss) return NULL; - memcpy(wdev->conn->bssid, bss->bssid, ETH_ALEN); - wdev->conn->params.bssid = wdev->conn->bssid; - wdev->conn->params.channel = bss->channel; - wdev->conn->state = CFG80211_CONN_AUTHENTICATE_NEXT; + cfg80211_step_auth_next(wdev->conn, bss); schedule_work(&rdev->conn_work); return bss; @@ -597,7 +603,12 @@ static int cfg80211_sme_connect(struct w wdev->conn->params.ssid_len = wdev->u.client.ssid_len; /* see if we have the bss already */ - bss = cfg80211_get_conn_bss(wdev); + bss = cfg80211_get_bss(wdev->wiphy, wdev->conn->params.channel, + wdev->conn->params.bssid, + wdev->conn->params.ssid, + wdev->conn->params.ssid_len, + wdev->conn_bss_type, + IEEE80211_PRIVACY(wdev->conn->params.privacy)); if (prev_bssid) { memcpy(wdev->conn->prev_bssid, prev_bssid, ETH_ALEN); @@ -608,6 +619,7 @@ static int cfg80211_sme_connect(struct w if (bss) { enum nl80211_timeout_reason treason; + cfg80211_step_auth_next(wdev->conn, bss); err = cfg80211_conn_do_work(wdev, &treason); cfg80211_put_bss(wdev->wiphy, bss); } else { @@ -1468,6 +1480,15 @@ int cfg80211_connect(struct cfg80211_reg } else { if (WARN_ON(connkeys)) return -EINVAL; + + /* connect can point to wdev->wext.connect which + * can hold key data from a previous connection + */ + connect->key = NULL; + connect->key_len = 0; + connect->key_idx = 0; + connect->crypto.cipher_group = 0; + connect->crypto.n_ciphers_pairwise = 0; } wdev->connect_keys = connkeys; Patches currently in stable-queue which might be from alexander@xxxxxxxxxxxxxx are queue-6.2/wifi-cfg80211-fix-use-after-free-for-wext.patch