Linux KernelOperating system · Linux
CVE-2026-43211
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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]]
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisShared resources are accessed without correct locking, so concurrent operations interleave into inconsistent — and sometimes exploitable — states, or deadlock the service outright. These bugs are subtle and timing-dependent. The fix is correct, consistent locking or atomic operations around every shared resource.
General guidance for the improper locking class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 4.19.322, < 4.20>= 5.4.284, < 5.5>= 5.10.226, < 5.10.252>= 5.15.167, < 5.15.202>= 6.1.110, < 6.1.165>= 6.6.51, < 6.6.128>= 6.10.10, < 6.12.75>= 6.13, < 6.18.16>= 6.19, < 6.19.6CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.205.55.10.252
For 4.19.x users: upgrade to 5.0 or later (4.20 had very short support); For 5.4.x users: upgrade to 5.5 or later; For 5.10.x users: upgrade to 5.10.252 or later; For 5.15.x users: upgrade to 5.15.202 or later
- Identify the current running kernel version using `uname -r`
- Compare the kernel version against the affected ranges: 4.19.322-4.19.x, 5.4.284-5.4.x, 5.10.226-5.10.251, or 5.15.167-5.15.201
- If affected, schedule a maintenance window for kernel upgrade
- Upgrade the Linux kernel to a version that includes the fix: 4.20 or later for 4.19.x users, 5.5 or later for 5.4.x users, 5.10.252 or later for 5.10.x users, or 5.15.202 or later for 5.15.x users
- Reboot the system into the new kernel
- Verify the fix is applied by checking the kernel version and confirming pci_slot_trylock() behavior is correct
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-43211 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-43211 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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