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From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH] wifi: nl80211: move WPA version validation to policy
Date: Mon, 29 Jan 2024 19:54:21 +0100
Message-ID: <20240129195421.e8cae9866ccb.I2539b395e3476307d702c6867e51a937e52e57a0@changeid>
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From: Johannes Berg <johannes.berg@intel.com>

For a contiguous mask (starting with bit 0) of allowed values
in a bitmap, it's equivalent to check "!(val & ~mask)" and
"val ∈ [0, mask]". Use that to move the WPA versions check to
the policy, for better error reporting.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/wireless/nl80211.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1331e39da0e6..b533412ad1e0 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5,7 +5,7 @@
  * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright 2015-2017	Intel Deutschland GmbH
- * Copyright (C) 2018-2023 Intel Corporation
+ * Copyright (C) 2018-2024 Intel Corporation
  */
 
 #include <linux/if.h>
@@ -581,7 +581,11 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_PRIVACY] = { .type = NLA_FLAG },
 	[NL80211_ATTR_STATUS_CODE] = { .type = NLA_U16 },
 	[NL80211_ATTR_CIPHER_SUITE_GROUP] = { .type = NLA_U32 },
-	[NL80211_ATTR_WPA_VERSIONS] = { .type = NLA_U32 },
+	[NL80211_ATTR_WPA_VERSIONS] =
+		NLA_POLICY_RANGE(NLA_U32, 0,
+				 NL80211_WPA_VERSION_1 |
+				 NL80211_WPA_VERSION_2 |
+				 NL80211_WPA_VERSION_3),
 	[NL80211_ATTR_PID] = { .type = NLA_U32 },
 	[NL80211_ATTR_4ADDR] = { .type = NLA_U8 },
 	[NL80211_ATTR_PMKID] = NLA_POLICY_EXACT_LEN_WARN(WLAN_PMKID_LEN),
@@ -10590,13 +10594,6 @@ static int nl80211_dump_survey(struct sk_buff *skb, struct netlink_callback *cb)
 	return res;
 }
 
-static bool nl80211_valid_wpa_versions(u32 wpa_versions)
-{
-	return !(wpa_versions & ~(NL80211_WPA_VERSION_1 |
-				  NL80211_WPA_VERSION_2 |
-				  NL80211_WPA_VERSION_3));
-}
-
 static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -10822,12 +10819,9 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
 			return -EINVAL;
 	}
 
-	if (info->attrs[NL80211_ATTR_WPA_VERSIONS]) {
+	if (info->attrs[NL80211_ATTR_WPA_VERSIONS])
 		settings->wpa_versions =
 			nla_get_u32(info->attrs[NL80211_ATTR_WPA_VERSIONS]);
-		if (!nl80211_valid_wpa_versions(settings->wpa_versions))
-			return -EINVAL;
-	}
 
 	if (info->attrs[NL80211_ATTR_AKM_SUITES]) {
 		void *data;
-- 
2.43.0