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From:   gregory.greenman@intel.com
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org,
        Johannes Berg <johannes.berg@intel.com>,
        Gregory Greenman <gregory.greenman@intel.com>
Subject: [PATCH 7/9] wifi: mac80211: fix CRC calculation for extended elems
Date:   Mon, 19 Jun 2023 16:26:51 +0300
Message-Id: <20230619161906.93235d5c8651.I6615cb3c1244bc9618066baa2bdad7982e9abd1f@changeid>
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From: Johannes Berg <johannes.berg@intel.com>

For extended elements, we currently only calculate the CRC
for some of them, but really we should do it also for the
rest that we care about, such as EHT operation and multi-
link.

Also, while at it, it seems we should do it even if they
aren't well-formed, so we notice if that changes.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
---
 net/mac80211/util.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 35701316dccf..516e68a39b7d 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -918,6 +918,7 @@ ieee80211_parse_extension_element(u32 *crc,
 				  struct ieee80211_elems_parse_params *params)
 {
 	const void *data = elem->data + 1;
+	bool calc_crc = false;
 	u8 len;
 
 	if (!elem->datalen)
@@ -927,12 +928,9 @@ ieee80211_parse_extension_element(u32 *crc,
 
 	switch (elem->data[0]) {
 	case WLAN_EID_EXT_HE_MU_EDCA:
-		if (len >= sizeof(*elems->mu_edca_param_set)) {
+		calc_crc = true;
+		if (len >= sizeof(*elems->mu_edca_param_set))
 			elems->mu_edca_param_set = data;
-			if (crc)
-				*crc = crc32_be(*crc, (void *)elem,
-						elem->datalen + 2);
-		}
 		break;
 	case WLAN_EID_EXT_HE_CAPABILITY:
 		if (ieee80211_he_capa_size_ok(data, len)) {
@@ -941,13 +939,10 @@ ieee80211_parse_extension_element(u32 *crc,
 		}
 		break;
 	case WLAN_EID_EXT_HE_OPERATION:
+		calc_crc = true;
 		if (len >= sizeof(*elems->he_operation) &&
-		    len >= ieee80211_he_oper_size(data) - 1) {
-			if (crc)
-				*crc = crc32_be(*crc, (void *)elem,
-						elem->datalen + 2);
+		    len >= ieee80211_he_oper_size(data) - 1)
 			elems->he_operation = data;
-		}
 		break;
 	case WLAN_EID_EXT_UORA:
 		if (len >= 1)
@@ -981,16 +976,15 @@ ieee80211_parse_extension_element(u32 *crc,
 	case WLAN_EID_EXT_EHT_OPERATION:
 		if (ieee80211_eht_oper_size_ok(data, len))
 			elems->eht_operation = data;
+		calc_crc = true;
 		break;
 	case WLAN_EID_EXT_EHT_MULTI_LINK:
+		calc_crc = true;
+
 		if (ieee80211_mle_size_ok(data, len)) {
 			const struct ieee80211_multi_link_elem *mle =
 				(void *)data;
 
-			if (crc)
-				*crc = crc32_be(*crc, (void *)elem,
-						elem->datalen + 2);
-
 			switch (le16_get_bits(mle->control,
 					      IEEE80211_ML_CONTROL_TYPE)) {
 			case IEEE80211_ML_CONTROL_TYPE_BASIC:
@@ -1009,6 +1003,9 @@ ieee80211_parse_extension_element(u32 *crc,
 		}
 		break;
 	}
+
+	if (crc && calc_crc)
+		*crc = crc32_be(*crc, (void *)elem, elem->datalen + 2);
 }
 
 static u32
-- 
2.38.1