CVE-2026-43211
Analyzed
Analyzed - Analysis Complete
PCI Lock Handling Flaw in Linux Kernel
Publication date: 2026-05-06
Last updated on: 2026-05-11
Assigner: kernel.org
Description
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_dev_unlock(dev) on the failure
path.
[Same patch later posted by Keith at
https://patch.msgid.link/[email protected]]
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 5.4.284 (inc) to 5.5 (exc) |
| linux | linux_kernel | From 4.19.322 (inc) to 4.20 (exc) |
| linux | linux_kernel | From 6.13 (inc) to 6.18.16 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 6.19.6 (exc) |
| linux | linux_kernel | From 5.10.226 (inc) to 5.10.252 (exc) |
| linux | linux_kernel | From 5.15.167 (inc) to 5.15.202 (exc) |
| linux | linux_kernel | From 6.1.110 (inc) to 6.1.165 (exc) |
| linux | linux_kernel | From 6.10.10 (inc) to 6.12.75 (exc) |
| linux | linux_kernel | From 6.6.51 (inc) to 6.6.128 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-667 | The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. |
