2021-02-02 15:22:47

by Sasha Levin

[permalink] [raw]
Subject: [PATCH AUTOSEL 4.4 3/5] iwlwifi: mvm: guard against device removal in reprobe

From: Johannes Berg <[email protected]>

[ 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 <[email protected]>
Signed-off-by: Luca Coelho <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/iwlwifi.20210122144849.871f0892e4b2.I94819e11afd68d875f3e242b98bef724b8236f1e@changeid
Signed-off-by: Sasha Levin <[email protected]>
drivers/net/wireless/iwlwifi/mvm/ops.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/iwlwifi/mvm/ops.c b/drivers/net/wireless/iwlwifi/mvm/ops.c
index 13c97f665ba88..bb81261de45fa 100644
--- a/drivers/net/wireless/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/iwlwifi/mvm/ops.c
@@ -909,6 +909,7 @@ 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);
@@ -991,7 +992,7 @@ void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error)
- reprobe->dev = mvm->trans->dev;
+ reprobe->dev = get_device(mvm->trans->dev);
INIT_WORK(&reprobe->work, iwl_mvm_reprobe_wk);
} else if (mvm->cur_ucode == IWL_UCODE_REGULAR) {