CVE-2026-43211

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]]

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-667 CWE-667

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.19.322 — 4.20
linux	linux_kernel	5.4.284 — 5.5
linux	linux_kernel	5.10.226 — 5.10.252
linux	linux_kernel	5.15.167 — 5.15.202
linux	linux_kernel	6.1.110 — 6.1.165
linux	linux_kernel	6.6.51 — 6.6.128
linux	linux_kernel	6.10.10 — 6.12.75
linux	linux_kernel	6.13 — 6.18.16
linux	linux_kernel	6.19 — 6.19.6

References

Advisories & Patches

https://git.kernel.org/stable/c/0425aaf20b407d2f2cf3bf469808e4a35f9abb8b https://git.kernel.org/stable/c/8b08ea9690b212b7bf7f12414039259cf34b1aa0 https://git.kernel.org/stable/c/9368d1ee62829b08aa31836b3ca003803caf0b72 https://git.kernel.org/stable/c/943ed56606a7ab2fe5a99cad572dd17d484310c7 https://git.kernel.org/stable/c/a19b61fdb958ffadbba85b43c991eb9fc70c1c1c https://git.kernel.org/stable/c/bd435f4b738130d732ef64e0e57e45185f77165d https://git.kernel.org/stable/c/ebb27b7399ab8b9eb1f792b329aa5f6250c590d4 https://git.kernel.org/stable/c/fbe06a3058114bf95a17a4941b205f4b321c6f0a

Frequently Asked Questions

What is CVE-2026-43211? +

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]] It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-43211? +

CVE-2026-43211 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-43211? +

CVE-2026-43211 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-43211? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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