[PATCH v2] nl80211: Avoid NL80211_WPA_VERSION_3 on older kernel versions

[benjamin at sipsolutions.net]

From: Benjamin Berg <benjamin.berg at intel.com>

NL80211_WPA_VERSION_3 was only added in kernel 5.2 so it should not be
set for older kernel versions.  There is no direct way to check if the
value is supported. However, we can use the new infrastructure to check
whether the kernel has the NL80211_ATTR_SAE_PASSWORD attribute. It is
related and was added at the same time.

Fixes: 6cc78b3945d3 ("nl80211: Set NL80211_WPA_VERSION_2 vs. _3 based on AKM")
Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>

---

v2:
 * Forgot Signed-off-by
---
 src/drivers/driver_nl80211.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 758d59722..97ce7a030 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -6854,7 +6854,13 @@ static int nl80211_connect_common(struct wpa_driver_nl80211_data *drv,
 		if (params->wpa_proto & WPA_PROTO_WPA)
 			ver |= NL80211_WPA_VERSION_1;
 		if (params->wpa_proto & WPA_PROTO_RSN) {
-			if (wpa_key_mgmt_sae(params->key_mgmt_suite))
+			/*
+			 * NL80211_ATTR_SAE_PASSWORD is related and was added
+			 * at the same time as NL80211_WPA_VERSION_3.
+			 */
+			if (nl80211_attr_supported(
+				drv, NL80211_ATTR_SAE_PASSWORD) &&
+			    wpa_key_mgmt_sae(params->key_mgmt_suite))
 				ver |= NL80211_WPA_VERSION_3;
 			else
 				ver |= NL80211_WPA_VERSION_2;
-- 
2.43.0