diff mbox series

[M/N] wifi: iwlwifi: pcie: rescan bus if no parent

Message ID 20240103031916.782306-3-kai.heng.feng@canonical.com
State New
Headers show
Series Fix NULL pointer dereference caused by Intel WiFi | expand

Commit Message

Kai-Heng Feng Jan. 3, 2024, 3:19 a.m. UTC 
From: Johannes Berg <johannes.berg@intel.com>

BugLink: https://bugs.launchpad.net/bugs/2046217

If the bus has no parent due to the topology, the device rescan
(after some kind of reset was detected) wouldn't work. On the
other hand, some platforms appear to require scanning the parent,
though it's not clear why.

However if there's no parent, then we skip the rescan, which isn't a
good idea. Change the code to go to the parent only if that exists,
and rescan the bus itself where it doesn't.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230913145231.f7795a1ccdab.I2b84810a743469a1bcabf3628262cf54311593f4@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
(cherry picked from commit 111ed1eb175754a9ef11811240329ca40db2072f)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 583d1011963e..86f6cb5af691 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -2113,8 +2113,11 @@  static void iwl_trans_pcie_removal_wk(struct work_struct *wk)
 	pci_lock_rescan_remove();
 	pci_dev_put(pdev);
 	pci_stop_and_remove_bus_device(pdev);
-	if (removal->rescan)
-		pci_rescan_bus(bus->parent);
+	if (removal->rescan && bus) {
+		if (bus->parent)
+			bus = bus->parent;
+		pci_rescan_bus(bus);
+	}
 	pci_unlock_rescan_remove();
 
 	kfree(removal);