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 Cc: stable@vger.kernel.org ---
v2: - Improve changelog (Lukas) - Added Cc stable
drivers/pci/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4d7c9f64ea24..26507aa906d7 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5542,7 +5542,8 @@ static void pci_slot_unlock(struct pci_slot *slot) continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate); - pci_dev_unlock(dev); + else + pci_dev_unlock(dev); } }
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
On 5/5/25 4:54 AM, Ilpo Järvinen wrote:
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 Cc: stable@vger.kernel.org
Reviewed-by: Dave Jiang dave.jiang@intel.com
v2:
- Improve changelog (Lukas)
- Added Cc stable
drivers/pci/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4d7c9f64ea24..26507aa906d7 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5542,7 +5542,8 @@ static void pci_slot_unlock(struct pci_slot *slot) continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
elsepci_dev_unlock(dev);}
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
On Mon, May 05, 2025 at 02:54:12PM +0300, Ilpo Järvinen wrote:
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 Cc: stable@vger.kernel.org
Applied to pci/reset for v6.16, thanks!
v2:
- Improve changelog (Lukas)
- Added Cc stable
drivers/pci/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4d7c9f64ea24..26507aa906d7 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -5542,7 +5542,8 @@ static void pci_slot_unlock(struct pci_slot *slot) continue; if (dev->subordinate) pci_bus_unlock(dev->subordinate);
pci_dev_unlock(dev);
elsepci_dev_unlock(dev);}
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
2.39.5
linux-stable-mirror@lists.linaro.org
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Bjorn Helgaas -
Dave Jiang -
Ilpo Järvinen