iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap

BugLink: https://bugs.launchpad.net/bugs/1918158
[ Upstream commit 98c7d21f957b10d9c07a3a60a3a5a8f326a197e5 ]

I hit a NULL pointer exception in this function when the
init flow went really bad.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20210115130252.2e8da9f2c132.I0234d4b8ddaf70aaa5028a20c863255e05bc1f84@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
index b5bfa2030572e35060f70256fcdbbfebfc582dd8..824c7dc827874c3fa9ef55f95581cdbfb44586f2 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx.c
@@ -657,6 +657,11 @@ static void iwl_pcie_txq_unmap(struct iwl_trans *trans, int txq_id)
        struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
        struct iwl_txq *txq = trans_pcie->txq[txq_id];
 
+       if (!txq) {
+               IWL_ERR(trans, "Trying to free a queue that wasn't allocated?\n");
+               return;
+       }
+
        spin_lock_bh(&txq->lock);
        while (txq->write_ptr != txq->read_ptr) {
                IWL_DEBUG_TX_REPLY(trans, "Q %d Free %d\n",