iwlwifi: mvm: guard against device removal in reprobe
authorJohannes Berg <johannes.berg@intel.com>
Fri, 22 Jan 2021 12:52:41 +0000 (14:52 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 13 Feb 2021 12:55:11 +0000 (13:55 +0100)
[ Upstream commit 7a21b1d4a728a483f07c638ccd8610d4b4f12684 ]

If we get into a problem severe enough to attempt a reprobe,
we schedule a worker to do that. However, if the problem gets
more severe and the device is actually destroyed before this
worker has a chance to run, we use a free device. Bump up the
reference count of the device until the worker runs to avoid
this situation.

Signed-off-by: Johannes Berg <johannes.berg@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.20210122144849.871f0892e4b2.I94819e11afd68d875f3e242b98bef724b8236f1e@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/net/wireless/intel/iwlwifi/mvm/ops.c

index cea8e397fe0f2ae422dd7ccb6bd5d2e6c7f6d4bd..cb83490f1016ff7f205f6f5dc91c537034e01dd0 100644 (file)
@@ -1249,6 +1249,7 @@ static void iwl_mvm_reprobe_wk(struct work_struct *wk)
        reprobe = container_of(wk, struct iwl_mvm_reprobe, work);
        if (device_reprobe(reprobe->dev))
                dev_err(reprobe->dev, "reprobe failed!\n");
+       put_device(reprobe->dev);
        kfree(reprobe);
        module_put(THIS_MODULE);
 }
@@ -1299,7 +1300,7 @@ void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error)
                        module_put(THIS_MODULE);
                        return;
                }
-               reprobe->dev = mvm->trans->dev;
+               reprobe->dev = get_device(mvm->trans->dev);
                INIT_WORK(&reprobe->work, iwl_mvm_reprobe_wk);
                schedule_work(&reprobe->work);
        } else if (test_bit(IWL_MVM_STATUS_HW_RESTART_REQUESTED,