From 015b8cc5e7c4d7bb671f1984d7b7338c310b185b Mon Sep 17 00:00:00 2001 From: Alexander Wetzel Date: Tue, 24 Jan 2023 15:18:56 +0100 Subject: wifi: cfg80211: Fix use after free for wext 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@vger.kernel.org Link: https://lore.kernel.org/r/20230124141856.356646-1-alexander@wetzel-home.de Signed-off-by: Alexander Wetzel Signed-off-by: Johannes Berg --- net/wireless/sme.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 123248b2c0be..0cc841c0c59b 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -285,6 +285,15 @@ void cfg80211_conn_work(struct work_struct *work) 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_conn_bss(struct wireless_dev *wdev) 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 wireless_dev *wdev, 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 wireless_dev *wdev, 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 { @@ -1464,6 +1476,15 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev, } 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; -- cgit v1.2.3