Merge branch 'cve-fixes-2022-10-13'

Pull in the fixes for various scan parsing bugs found by
Sönke Huster by fuzzing.

3 files changed, 32 insertions, 20 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4e1d4c339f2d..a842f2e1c230 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1709,6 +1709,14 @@ struct ieee802_11_elems {
 
 	/* whether a parse error occurred while retrieving these elements */
 	bool parse_error;
+
+	/*
+	 * scratch buffer that can be used for various element parsing related
+	 * tasks, e.g., element de-fragmentation etc.
+	 */
+	size_t scratch_len;
+	u8 *scratch_pos;
+	u8 scratch[];
 };
 
 static inline struct ieee80211_local *hw_to_local(
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 589521717c35..f99416d2e144 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1978,10 +1978,11 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 
 		if (mmie_keyidx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS ||
 		    mmie_keyidx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
-		    NUM_DEFAULT_BEACON_KEYS) {
-			cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
-						     skb->data,
-						     skb->len);
+				   NUM_DEFAULT_BEACON_KEYS) {
+			if (rx->sdata->dev)
+				cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
+							     skb->data,
+							     skb->len);
 			return RX_DROP_MONITOR; /* unexpected BIP keyidx */
 		}
 
@@ -2131,7 +2132,8 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
 	/* either the frame has been decrypted or will be dropped */
 	status->flag |= RX_FLAG_DECRYPTED;
 
-	if (unlikely(ieee80211_is_beacon(fc) && result == RX_DROP_UNUSABLE))
+	if (unlikely(ieee80211_is_beacon(fc) && result == RX_DROP_UNUSABLE &&
+		     rx->sdata->dev))
 		cfg80211_rx_unprot_mlme_mgmt(rx->sdata->dev,
 					     skb->data, skb->len);
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 1e929b82deef..b512cb37aafb 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1445,6 +1445,8 @@ static size_t ieee802_11_find_bssid_profile(const u8 *start, size_t len,
 	for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, start, len) {
 		if (elem->datalen < 2)
 			continue;
+		if (elem->data[0] < 1 || elem->data[0] > 8)
+			continue;
 
 		for_each_element(sub, elem->data + 1, elem->datalen - 1) {
 			u8 new_bssid[ETH_ALEN];
@@ -1504,24 +1506,26 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params)
 	const struct element *non_inherit = NULL;
 	u8 *nontransmitted_profile;
 	int nontransmitted_profile_len = 0;
+	size_t scratch_len = params->len;
 
-	elems = kzalloc(sizeof(*elems), GFP_ATOMIC);
+	elems = kzalloc(sizeof(*elems) + scratch_len, GFP_ATOMIC);
 	if (!elems)
 		return NULL;
 	elems->ie_start = params->start;
 	elems->total_len = params->len;
-
-	nontransmitted_profile = kmalloc(params->len, GFP_ATOMIC);
-	if (nontransmitted_profile) {
-		nontransmitted_profile_len =
-			ieee802_11_find_bssid_profile(params->start, params->len,
-						      elems, params->bss,
-						      nontransmitted_profile);
-		non_inherit =
-			cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
-					       nontransmitted_profile,
-					       nontransmitted_profile_len);
-	}
+	elems->scratch_len = scratch_len;
+	elems->scratch_pos = elems->scratch;
+
+	nontransmitted_profile = elems->scratch_pos;
+	nontransmitted_profile_len =
+		ieee802_11_find_bssid_profile(params->start, params->len,
+					      elems, params->bss,
+					      nontransmitted_profile);
+	elems->scratch_pos += nontransmitted_profile_len;
+	elems->scratch_len -= nontransmitted_profile_len;
+	non_inherit = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
+					     nontransmitted_profile,
+					     nontransmitted_profile_len);
 
 	elems->crc = _ieee802_11_parse_elems_full(params, elems, non_inherit);
 
@@ -1555,8 +1559,6 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params)
 	    offsetofend(struct ieee80211_bssid_index, dtim_count))
 		elems->dtim_count = elems->bssid_index->dtim_count;
 
-	kfree(nontransmitted_profile);
-
 	return elems;
 }