[PATCH AUTOSEL 5.14 233/252] iwlwifi: mvm: fix access to BSS elements

Sasha Levin
2021-09-09T12:05:21Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 6c608cd6962ebdf84fd3de6d42f88ed64d2f4e1b ]

BSS elements are protected using RCU, so we need to use
RCU properly to access them, fix that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210805130823.fd8b5791ab44.Iba26800a6301078d3782fb249c476dd8ac2bf3c6@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index 70ebecb73c24..79f44435972e 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -2987,16 +2987,20 @@ static void iwl_mvm_check_he_obss_narrow_bw_ru_iter(struct wiphy *wiphy,
void *_data)
{
struct iwl_mvm_he_obss_narrow_bw_ru_data *data = _data;
+ const struct cfg80211_bss_ies *ies;
const struct element *elem;

- elem = cfg80211_find_elem(WLAN_EID_EXT_CAPABILITY, bss->ies->data,
- bss->ies->len);
+ rcu_read_lock();
+ ies = rcu_dereference(bss->ies);
+ elem = cfg80211_find_elem(WLAN_EID_EXT_CAPABILITY, ies->data,
+ ies->len);

if (!elem || elem->datalen < 10 ||
!(elem->data[10] &
WLAN_EXT_CAPA10_OBSS_NARROW_BW_RU_TOLERANCE_SUPPORT)) {
data->tolerated = false;
}
+ rcu_read_unlock();
}

static void iwl_mvm_check_he_obss_narrow_bw_ru(struct ieee80211_hw *hw,
--
2.30.2