1 files changed, 176 insertions, 111 deletions

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 6bb9437af28b..a1c53d4b6711 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -104,18 +104,12 @@ static inline void bss_ref_get(struct cfg80211_registered_device *rdev,
 	lockdep_assert_held(&rdev->bss_lock);
 
 	bss->refcount++;
-	if (bss->pub.hidden_beacon_bss) {
-		bss = container_of(bss->pub.hidden_beacon_bss,
-				   struct cfg80211_internal_bss,
-				   pub);
-		bss->refcount++;
-	}
-	if (bss->pub.transmitted_bss) {
-		bss = container_of(bss->pub.transmitted_bss,
-				   struct cfg80211_internal_bss,
-				   pub);
-		bss->refcount++;
-	}
+
+	if (bss->pub.hidden_beacon_bss)
+		bss_from_pub(bss->pub.hidden_beacon_bss)->refcount++;
+
+	if (bss->pub.transmitted_bss)
+		bss_from_pub(bss->pub.transmitted_bss)->refcount++;
 }
 
 static inline void bss_ref_put(struct cfg80211_registered_device *rdev,
@@ -229,114 +223,152 @@ bool cfg80211_is_element_inherited(const struct element *elem,
 }
 EXPORT_SYMBOL(cfg80211_is_element_inherited);
 
-static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
-				  const u8 *subelement, size_t subie_len,
-				  u8 *new_ie, gfp_t gfp)
+static size_t cfg80211_copy_elem_with_frags(const struct element *elem,
+					    const u8 *ie, size_t ie_len,
+					    u8 **pos, u8 *buf, size_t buf_len)
 {
-	u8 *pos, *tmp;
-	const u8 *tmp_old, *tmp_new;
-	const struct element *non_inherit_elem;
-	u8 *sub_copy;
+	if (WARN_ON((u8 *)elem < ie || elem->data > ie + ie_len ||
+		    elem->data + elem->datalen > ie + ie_len))
+		return 0;
 
-	/* copy subelement as we need to change its content to
-	 * mark an ie after it is processed.
-	 */
-	sub_copy = kmemdup(subelement, subie_len, gfp);
-	if (!sub_copy)
+	if (elem->datalen + 2 > buf + buf_len - *pos)
 		return 0;
 
-	pos = &new_ie[0];
+	memcpy(*pos, elem, elem->datalen + 2);
+	*pos += elem->datalen + 2;
 
-	/* set new ssid */
-	tmp_new = cfg80211_find_ie(WLAN_EID_SSID, sub_copy, subie_len);
-	if (tmp_new) {
-		memcpy(pos, tmp_new, tmp_new[1] + 2);
-		pos += (tmp_new[1] + 2);
+	/* Finish if it is not fragmented  */
+	if (elem->datalen != 255)
+		return *pos - buf;
+
+	ie_len = ie + ie_len - elem->data - elem->datalen;
+	ie = (const u8 *)elem->data + elem->datalen;
+
+	for_each_element(elem, ie, ie_len) {
+		if (elem->id != WLAN_EID_FRAGMENT)
+			break;
+
+		if (elem->datalen + 2 > buf + buf_len - *pos)
+			return 0;
+
+		memcpy(*pos, elem, elem->datalen + 2);
+		*pos += elem->datalen + 2;
+
+		if (elem->datalen != 255)
+			break;
 	}
 
-	/* get non inheritance list if exists */
-	non_inherit_elem =
-		cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
-				       sub_copy, subie_len);
+	return *pos - buf;
+}
 
-	/* go through IEs in ie (skip SSID) and subelement,
-	 * merge them into new_ie
+static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen,
+				  const u8 *subie, size_t subie_len,
+				  u8 *new_ie, size_t new_ie_len)
+{
+	const struct element *non_inherit_elem, *parent, *sub;
+	u8 *pos = new_ie;
+	u8 id, ext_id;
+	unsigned int match_len;
+
+	non_inherit_elem = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
+						  subie, subie_len);
+
+	/* We copy the elements one by one from the parent to the generated
+	 * elements.
+	 * If they are not inherited (included in subie or in the non
+	 * inheritance element), then we copy all occurrences the first time
+	 * we see this element type.
 	 */
-	tmp_old = cfg80211_find_ie(WLAN_EID_SSID, ie, ielen);
-	tmp_old = (tmp_old) ? tmp_old + tmp_old[1] + 2 : ie;
-
-	while (tmp_old + tmp_old[1] + 2 - ie <= ielen) {
-		if (tmp_old[0] == 0) {
-			tmp_old++;
+	for_each_element(parent, ie, ielen) {
+		if (parent->id == WLAN_EID_FRAGMENT)
 			continue;
+
+		if (parent->id == WLAN_EID_EXTENSION) {
+			if (parent->datalen < 1)
+				continue;
+
+			id = WLAN_EID_EXTENSION;
+			ext_id = parent->data[0];
+			match_len = 1;
+		} else {
+			id = parent->id;
+			match_len = 0;
 		}
 
-		if (tmp_old[0] == WLAN_EID_EXTENSION)
-			tmp = (u8 *)cfg80211_find_ext_ie(tmp_old[2], sub_copy,
-							 subie_len);
-		else
-			tmp = (u8 *)cfg80211_find_ie(tmp_old[0], sub_copy,
-						     subie_len);
+		/* Find first occurrence in subie */
+		sub = cfg80211_find_elem_match(id, subie, subie_len,
+					       &ext_id, match_len, 0);
 
-		if (!tmp) {
-			const struct element *old_elem = (void *)tmp_old;
+		/* Copy from parent if not in subie and inherited */
+		if (!sub &&
+		    cfg80211_is_element_inherited(parent, non_inherit_elem)) {
+			if (!cfg80211_copy_elem_with_frags(parent,
+							   ie, ielen,
+							   &pos, new_ie,
+							   new_ie_len))
+				return 0;
 
-			/* ie in old ie but not in subelement */
-			if (cfg80211_is_element_inherited(old_elem,
-							  non_inherit_elem)) {
-				memcpy(pos, tmp_old, tmp_old[1] + 2);
-				pos += tmp_old[1] + 2;
-			}
-		} else {
-			/* ie in transmitting ie also in subelement,
-			 * copy from subelement and flag the ie in subelement
-			 * as copied (by setting eid field to WLAN_EID_SSID,
-			 * which is skipped anyway).
-			 * For vendor ie, compare OUI + type + subType to
-			 * determine if they are the same ie.
-			 */
-			if (tmp_old[0] == WLAN_EID_VENDOR_SPECIFIC) {
-				if (!memcmp(tmp_old + 2, tmp + 2, 5)) {
-					/* same vendor ie, copy from
-					 * subelement
-					 */
-					memcpy(pos, tmp, tmp[1] + 2);
-					pos += tmp[1] + 2;
-					tmp[0] = WLAN_EID_SSID;
-				} else {
-					memcpy(pos, tmp_old, tmp_old[1] + 2);
-					pos += tmp_old[1] + 2;
-				}
-			} else {
-				/* copy ie from subelement into new ie */
-				memcpy(pos, tmp, tmp[1] + 2);
-				pos += tmp[1] + 2;
-				tmp[0] = WLAN_EID_SSID;
-			}
+			continue;
 		}
 
-		if (tmp_old + tmp_old[1] + 2 - ie == ielen)
-			break;
+		/* Already copied if an earlier element had the same type */
+		if (cfg80211_find_elem_match(id, ie, (u8 *)parent - ie,
+					     &ext_id, match_len, 0))
+			continue;
 
-		tmp_old += tmp_old[1] + 2;
+		/* Not inheriting, copy all similar elements from subie */
+		while (sub) {
+			if (!cfg80211_copy_elem_with_frags(sub,
+							   subie, subie_len,
+							   &pos, new_ie,
+							   new_ie_len))
+				return 0;
+
+			sub = cfg80211_find_elem_match(id,
+						       sub->data + sub->datalen,
+						       subie_len + subie -
+						       (sub->data +
+							sub->datalen),
+						       &ext_id, match_len, 0);
+		}
 	}
 
-	/* go through subelement again to check if there is any ie not
-	 * copied to new ie, skip ssid, capability, bssid-index ie
+	/* The above misses elements that are included in subie but not in the
+	 * parent, so do a pass over subie and append those.
+	 * Skip the non-tx BSSID caps and non-inheritance element.
 	 */
-	tmp_new = sub_copy;
-	while (tmp_new + tmp_new[1] + 2 - sub_copy <= subie_len) {
-		if (!(tmp_new[0] == WLAN_EID_NON_TX_BSSID_CAP ||
-		      tmp_new[0] == WLAN_EID_SSID)) {
-			memcpy(pos, tmp_new, tmp_new[1] + 2);
-			pos += tmp_new[1] + 2;
+	for_each_element(sub, subie, subie_len) {
+		if (sub->id == WLAN_EID_NON_TX_BSSID_CAP)
+			continue;
+
+		if (sub->id == WLAN_EID_FRAGMENT)
+			continue;
+
+		if (sub->id == WLAN_EID_EXTENSION) {
+			if (sub->datalen < 1)
+				continue;
+
+			id = WLAN_EID_EXTENSION;
+			ext_id = sub->data[0];
+			match_len = 1;
+
+			if (ext_id == WLAN_EID_EXT_NON_INHERITANCE)
+				continue;
+		} else {
+			id = sub->id;
+			match_len = 0;
 		}
-		if (tmp_new + tmp_new[1] + 2 - sub_copy == subie_len)
-			break;
-		tmp_new += tmp_new[1] + 2;
+
+		/* Processed if one was included in the parent */
+		if (cfg80211_find_elem_match(id, ie, ielen,
+					     &ext_id, match_len, 0))
+			continue;
+
+		if (!cfg80211_copy_elem_with_frags(sub, subie, subie_len,
+						   &pos, new_ie, new_ie_len))
+			return 0;
 	}
 
-	kfree(sub_copy);
 	return pos - new_ie;
 }
 
@@ -390,6 +422,15 @@ cfg80211_add_nontrans_list(struct cfg80211_bss *trans_bss,
 
 	rcu_read_unlock();
 
+	/*
+	 * This is a bit weird - it's not on the list, but already on another
+	 * one! The only way that could happen is if there's some BSSID/SSID
+	 * shared by multiple APs in their multi-BSSID profiles, potentially
+	 * with hidden SSID mixed in ... ignore it.
+	 */
+	if (!list_empty(&nontrans_bss->nontrans_list))
+		return -EINVAL;
+
 	/* add to the list */
 	list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list);
 	return 0;
@@ -1094,6 +1135,23 @@ struct cfg80211_non_tx_bss {
 	u8 bssid_index;
 };
 
+static void cfg80211_update_hidden_bsses(struct cfg80211_internal_bss *known,
+					 const struct cfg80211_bss_ies *new_ies,
+					 const struct cfg80211_bss_ies *old_ies)
+{
+	struct cfg80211_internal_bss *bss;
+
+	/* Assign beacon IEs to all sub entries */
+	list_for_each_entry(bss, &known->hidden_list, hidden_list) {
+		const struct cfg80211_bss_ies *ies;
+
+		ies = rcu_access_pointer(bss->pub.beacon_ies);
+		WARN_ON(ies != old_ies);
+
+		rcu_assign_pointer(bss->pub.beacon_ies, new_ies);
+	}
+}
+
 static bool
 cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
 			  struct cfg80211_internal_bss *known,
@@ -1117,7 +1175,6 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
 	} else if (rcu_access_pointer(new->pub.beacon_ies)) {
 		const struct cfg80211_bss_ies *old;
-		struct cfg80211_internal_bss *bss;
 
 		if (known->pub.hidden_beacon_bss &&
 		    !list_empty(&known->hidden_list)) {
@@ -1145,16 +1202,9 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
 		if (old == rcu_access_pointer(known->pub.ies))
 			rcu_assign_pointer(known->pub.ies, new->pub.beacon_ies);
 
-		/* Assign beacon IEs to all sub entries */
-		list_for_each_entry(bss, &known->hidden_list, hidden_list) {
-			const struct cfg80211_bss_ies *ies;
-
-			ies = rcu_access_pointer(bss->pub.beacon_ies);
-			WARN_ON(ies != old);
-
-			rcu_assign_pointer(bss->pub.beacon_ies,
-					   new->pub.beacon_ies);
-		}
+		cfg80211_update_hidden_bsses(known,
+					     rcu_access_pointer(new->pub.beacon_ies),
+					     old);
 
 		if (old)
 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);
@@ -1231,6 +1281,8 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 		new->refcount = 1;
 		INIT_LIST_HEAD(&new->hidden_list);
 		INIT_LIST_HEAD(&new->pub.nontrans_list);
+		/* we'll set this later if it was non-NULL */
+		new->pub.transmitted_bss = NULL;
 
 		if (rcu_access_pointer(tmp->pub.proberesp_ies)) {
 			hidden = rb_find_bss(rdev, tmp, BSS_CMP_HIDE_ZLEN);
@@ -1242,8 +1294,12 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
 				list_add(&new->hidden_list,
 					 &hidden->hidden_list);
 				hidden->refcount++;
+
+				ies = (void *)rcu_access_pointer(new->pub.beacon_ies);
 				rcu_assign_pointer(new->pub.beacon_ies,
 						   hidden->pub.beacon_ies);
+				if (ies)
+					kfree_rcu(ies, rcu_head);
 			}
 		} else {
 			/*
@@ -1460,10 +1516,15 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
 		spin_lock_bh(&rdev->bss_lock);
 		if (cfg80211_add_nontrans_list(non_tx_data->tx_bss,
 					       &res->pub)) {
-			if (__cfg80211_unlink_bss(rdev, res))
+			if (__cfg80211_unlink_bss(rdev, res)) {
 				rdev->bss_generation++;
+				res = NULL;
+			}
 		}
 		spin_unlock_bh(&rdev->bss_lock);
+
+		if (!res)
+			return NULL;
 	}
 
 	trace_cfg80211_return_bss(&res->pub);
@@ -1582,6 +1643,8 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
 	for_each_element_id(elem, WLAN_EID_MULTIPLE_BSSID, ie, ielen) {
 		if (elem->datalen < 4)
 			continue;
+		if (elem->data[0] < 1 || (int)elem->data[0] > 8)
+			continue;
 		for_each_element(sub, elem->data + 1, elem->datalen - 1) {
 			u8 profile_len;
 
@@ -1635,7 +1698,7 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy,
 			new_ie_len = cfg80211_gen_new_ie(ie, ielen,
 							 profile,
 							 profile_len, new_ie,
-							 gfp);
+							 IEEE80211_MAX_DATA_LEN);
 			if (!new_ie_len)
 				continue;
 
@@ -1717,7 +1780,7 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 	size_t new_ie_len;
 	struct cfg80211_bss_ies *new_ies;
 	const struct cfg80211_bss_ies *old;
-	u8 cpy_len;
+	size_t cpy_len;
 
 	lockdep_assert_held(&wiphy_to_rdev(wiphy)->bss_lock);
 
@@ -1784,6 +1847,8 @@ cfg80211_update_notlisted_nontrans(struct wiphy *wiphy,
 	} else {
 		old = rcu_access_pointer(nontrans_bss->beacon_ies);
 		rcu_assign_pointer(nontrans_bss->beacon_ies, new_ies);
+		cfg80211_update_hidden_bsses(bss_from_pub(nontrans_bss),
+					     new_ies, old);
 		rcu_assign_pointer(nontrans_bss->ies, new_ies);
 		if (old)
 			kfree_rcu((struct cfg80211_bss_ies *)old, rcu_head);