iwlwifi: mvm: sanity check context in iwl_mvm_phy_ctxt_unref()

In some botched (!) restart scenarios we seem to get here with
a NULL PHY context, so warn and exit instead of crashing.

Reported-by: Omer Kremer <omerx.kremer@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
index 0ea61aaf7754abfafaeb4ccc721b2ce4b3cd26ab..1b4db25d53fbab1272b0b6d1bbdf145349121502 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
+++ b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
@@ -245,5 +245,9 @@ int iwl_mvm_phy_ctxt_changed(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt,
 void iwl_mvm_phy_ctxt_unref(struct iwl_mvm *mvm, struct iwl_mvm_phy_ctxt *ctxt)
 {
        lockdep_assert_held(&mvm->mutex);
+
+       if (WARN_ON_ONCE(!ctxt))
+               return;
+
        ctxt->ref--;
 }