2021-02-02 15:56:40

by Sasha Levin

[permalink] [raw]
Subject: [PATCH AUTOSEL 5.4 12/17] iwlwifi: mvm: invalidate IDs of internal stations at mvm start

From: Gregory Greenman <[email protected]>

[ Upstream commit e223e42aac30bf81f9302c676cdf58cf2bf36950 ]

Having sta_id not set for aux_sta and snif_sta can potentially lead to a
hard to debug issue in case remove station is called without an add. In
this case sta_id 0, an unrelated regular station, will be removed.

In fact, we do have a FW assert that occures rarely and from the debug
data analysis it looks like sta_id 0 is removed by mistake, though it's
hard to pinpoint the exact flow. The WARN_ON in this patch should help
to find it.

Signed-off-by: Gregory Greenman <[email protected]>
Signed-off-by: Luca Coelho <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/iwlwifi.202101[email protected]changeid
Signed-off-by: Sasha Levin <[email protected]>
---
drivers/net/wireless/intel/iwlwifi/mvm/ops.c | 4 ++++
drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 6 ++++++
2 files changed, 10 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index b04cc6214bac8..bc25a59807c34 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -838,6 +838,10 @@ iwl_op_mode_mvm_start(struct iwl_trans *trans, const struct iwl_cfg *cfg,
if (!mvm->scan_cmd)
goto out_free;

+ /* invalidate ids to prevent accidental removal of sta_id 0 */
+ mvm->aux_sta.sta_id = IWL_MVM_INVALID_STA;
+ mvm->snif_sta.sta_id = IWL_MVM_INVALID_STA;
+
/* Set EBS as successful as long as not stated otherwise by the FW. */
mvm->last_ebs_successful = true;

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index a36aa9e85e0b3..40cafcf40ccf0 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -2070,6 +2070,9 @@ int iwl_mvm_rm_snif_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)

lockdep_assert_held(&mvm->mutex);

+ if (WARN_ON_ONCE(mvm->snif_sta.sta_id == IWL_MVM_INVALID_STA))
+ return -EINVAL;
+
iwl_mvm_disable_txq(mvm, NULL, mvm->snif_queue, IWL_MAX_TID_COUNT, 0);
ret = iwl_mvm_rm_sta_common(mvm, mvm->snif_sta.sta_id);
if (ret)
@@ -2084,6 +2087,9 @@ int iwl_mvm_rm_aux_sta(struct iwl_mvm *mvm)

lockdep_assert_held(&mvm->mutex);

+ if (WARN_ON_ONCE(mvm->aux_sta.sta_id == IWL_MVM_INVALID_STA))
+ return -EINVAL;
+
iwl_mvm_disable_txq(mvm, NULL, mvm->aux_queue, IWL_MAX_TID_COUNT, 0);
ret = iwl_mvm_rm_sta_common(mvm, mvm->aux_sta.sta_id);
if (ret)
--
2.27.0