5.15-stable review patch. If anyone has any objections, please let me know.
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From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
commit f3efb9569b4a21354ef2caf7ab0608a3e14cc6e4 upstream.
The commit a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()") made the lock function to call depend on dev->subordinate but left pci_slot_unlock() unmodified creating locking asymmetry compared with pci_slot_lock().
Because of the asymmetric lock handling, the same bridge device is unlocked twice. First pci_bus_unlock() unlocks bus->self and then pci_slot_unlock() will unconditionally unlock the same bridge device.
Move pci_dev_unlock() inside an else branch to match the logic in pci_slot_lock().
Fixes: a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()") Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Lukas Wunner lukas@wunner.de Reviewed-by: Dave Jiang dave.jiang@intel.com Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250505115412.37628-1-ilpo.jarvinen@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5593,7 +5593,8 @@ static void pci_slot_unlock(struct pci_s continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate); - pci_dev_unlock(dev); + else + pci_dev_unlock(dev); } }