[PATCH 5.15 054/177] iwlwifi: mvm: dont crash on invalid rate w/o STA

Greg Kroah-Hartman
2021-12-20T15:10:30Z

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

[ Upstream commit d599f714b73e4177dfdfe64fce09175568288ee9 ]

If we get to the WARN_ONCE(..., "Got a HT rate (...)", ...)
here with a NULL sta, then we crash because mvmsta is bad
and we try to dereference it. Fix that by printing -1 as the
state if no station was given.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 6761a718263a ("iwlwifi: mvm: add explicit check for non-data frames in get Tx rate")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/iwlwifi.20211203140410.1a1541d7dcb5.I606c746e11447fe168cf046376b70b04e278c3b4@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/intel/iwlwifi/mvm/tx.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 0a13c2bda2eed..06fbd9ab37dfe 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -268,17 +268,18 @@ static u32 iwl_mvm_get_tx_rate(struct iwl_mvm *mvm,
int rate_idx = -1;
u8 rate_plcp;
u32 rate_flags = 0;
- struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);

/* info->control is only relevant for non HW rate control */
if (!ieee80211_hw_check(mvm->hw, HAS_RATE_CONTROL)) {
+ struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
+
/* HT rate doesn't make sense for a non data frame */
WARN_ONCE(info->control.rates[0].flags & IEEE80211_TX_RC_MCS &&
!ieee80211_is_data(fc),
"Got a HT rate (flags:0x%x/mcs:%d/fc:0x%x/state:%d) for a non data frame\n",
info->control.rates[0].flags,
info->control.rates[0].idx,
- le16_to_cpu(fc), mvmsta->sta_state);
+ le16_to_cpu(fc), sta ? mvmsta->sta_state : -1);

rate_idx = info->control.rates[0].idx;
}
--
2.33.0