CVE-2026-43211

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

PCI: Fix pci_slot_trylock() error handling

Commit a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()")

delegates the bridge device's pci_dev_trylock() to pci_bus_trylock() in

pci_slot_trylock(), but it forgets to remove the corresponding

pci_dev_unlock() when pci_bus_trylock() fails.

Before a4e772898f8b, the code did:

if (!pci_dev_trylock(dev)) /* <- lock bridge device */

goto unlock;

if (dev->subordinate) {

if (!pci_bus_trylock(dev->subordinate)) {

pci_dev_unlock(dev); /* <- unlock bridge device */

goto unlock;

}

}

After a4e772898f8b the bridge-device lock is no longer taken, but the

pci_dev_unlock(dev) on the failure path was left in place, leading to the

bug.

This yields one of two errors:

1. A warning that the lock is being unlocked when no one holds it.

2. An incorrect unlock of a lock that belongs to another thread.

Fix it by removing the now-redundant pci_de

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References