[PATCH 6.6 197/638] wifi: iwlwifi: mvm: don't set the MFP flag for the GTK

Sasha Levin
2024-03-24T23:04:32Z

From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

[ Upstream commit e35f316bce9e5733c9826120c1838f4c447b2c4c ]

The firmware doesn't need the MFP flag for the GTK, it can even make the
firmware crash. in case the AP is configured with: group cipher TKIP and
MFPC. We would send the GTK with cipher = TKIP and MFP which is of course
not possible.

Fixes: 5c75a208c244 ("wifi: iwlwifi: mvm: support new key API")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240206175739.2f2c602ab3c6.If13b2e2fa532381d985c07df130bee1478046c89@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/intel/iwlwifi/mvm/mld-key.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mld-key.c b/drivers/net/wireless/intel/iwlwifi/mvm/mld-key.c
index ea3e9e9c6e26c..fe4b39b19a612 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mld-key.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mld-key.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
- * Copyright (C) 2022 - 2023 Intel Corporation
+ * Copyright (C) 2022 - 2024 Intel Corporation
*/
#include <linux/kernel.h>
#include <net/mac80211.h>
@@ -62,11 +62,13 @@ u32 iwl_mvm_get_sec_flags(struct iwl_mvm *mvm,
struct ieee80211_key_conf *keyconf)
{
struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+ bool pairwise = keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE;
+ bool igtk = keyconf->keyidx == 4 || keyconf->keyidx == 5;
u32 flags = 0;

lockdep_assert_held(&mvm->mutex);

- if (!(keyconf->flags & IEEE80211_KEY_FLAG_PAIRWISE))
+ if (!pairwise)
flags |= IWL_SEC_KEY_FLAG_MCAST_KEY;

switch (keyconf->cipher) {
@@ -96,12 +98,14 @@ u32 iwl_mvm_get_sec_flags(struct iwl_mvm *mvm,
if (!sta && vif->type == NL80211_IFTYPE_STATION)
sta = mvmvif->ap_sta;

- /* Set the MFP flag also for an AP interface where the key is an IGTK
- * key as in such a case the station would always be NULL
+ /*
+ * If we are installing an iGTK (in AP or STA mode), we need to tell
+ * the firmware this key will en/decrypt MGMT frames.
+ * Same goes if we are installing a pairwise key for an MFP station.
+ * In case we're installing a groupwise key (which is not an iGTK),
+ * then, we will not use this key for MGMT frames.
*/
- if ((!IS_ERR_OR_NULL(sta) && sta->mfp) ||
- (vif->type == NL80211_IFTYPE_AP &&
- (keyconf->keyidx == 4 || keyconf->keyidx == 5)))
+ if ((!IS_ERR_OR_NULL(sta) && sta->mfp && pairwise) || igtk)
flags |= IWL_SEC_KEY_FLAG_MFP;

return flags;
--
2.43.0