---
id: CVE-2026-43211
title: 'PCI: Fix pci_slot_trylock() error handling'
summary: |-
  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 pc…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e2355d513b89a2cb511b4ded0deb426cdb01acd0 <
    ebb27b7399ab8b9eb1f792b329aa5f6250c590d4
  - >-
    Linux >= 04e85a3285b0e5c5af6fd2c0fd6e95ffecc01945 <
    fbe06a3058114bf95a17a4941b205f4b321c6f0a
  - >-
    Linux >= 7253b4fed46471cc247c6cacefac890a8472c083 <
    943ed56606a7ab2fe5a99cad572dd17d484310c7
  - >-
    Linux >= 78c6e39fef5c428960aff742149bba302dd46f5a <
    a19b61fdb958ffadbba85b43c991eb9fc70c1c1c
  - >-
    Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab <
    0425aaf20b407d2f2cf3bf469808e4a35f9abb8b
  - >-
    Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab <
    bd435f4b738130d732ef64e0e57e45185f77165d
  - >-
    Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab <
    8b08ea9690b212b7bf7f12414039259cf34b1aa0
  - >-
    Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab <
    9368d1ee62829b08aa31836b3ca003803caf0b72
  - Linux 0790b89c7e911003b8c50ae50e3ac7645de1fae9
  - Linux df77a678c33871a6e4ac5b54a71662f1d702335b
  - Linux 81c68e218ab883dfa368460a59b674084c0240da
  - Linux >= 5.10.226 < 5.10.252
  - Linux >= 5.15.167 < 5.15.202
  - Linux >= 6.1.110 < 6.1.165
  - Linux >= 6.6.51 < 6.6.128
  - Linux >= 4.19.322 < 4.20
  - Linux >= 5.4.284 < 5.5
  - Linux >= 6.10.10 < 6.11
  - Linux 6.11
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:15:46.430223Z'
published: '2026-05-06'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:36.671Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43211'
references:
  - url: 'https://git.kernel.org/stable/c/ebb27b7399ab8b9eb1f792b329aa5f6250c590d4'
  - url: 'https://git.kernel.org/stable/c/fbe06a3058114bf95a17a4941b205f4b321c6f0a'
  - url: 'https://git.kernel.org/stable/c/943ed56606a7ab2fe5a99cad572dd17d484310c7'
  - url: 'https://git.kernel.org/stable/c/a19b61fdb958ffadbba85b43c991eb9fc70c1c1c'
  - url: 'https://git.kernel.org/stable/c/0425aaf20b407d2f2cf3bf469808e4a35f9abb8b'
  - url: 'https://git.kernel.org/stable/c/bd435f4b738130d732ef64e0e57e45185f77165d'
  - url: 'https://git.kernel.org/stable/c/8b08ea9690b212b7bf7f12414039259cf34b1aa0'
  - url: 'https://git.kernel.org/stable/c/9368d1ee62829b08aa31836b3ca003803caf0b72'
tags:
  - cve.org
epss: 0.00136
epssPercentile: 0.02689
ingestedAt: '2026-10-16T17:24:46.687Z'
---

## Overview

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/20260116184150.3013258-1-kbusch@meta.com]

## Affected

- `Linux >= e2355d513b89a2cb511b4ded0deb426cdb01acd0 < ebb27b7399ab8b9eb1f792b329aa5f6250c590d4`
- `Linux >= 04e85a3285b0e5c5af6fd2c0fd6e95ffecc01945 < fbe06a3058114bf95a17a4941b205f4b321c6f0a`
- `Linux >= 7253b4fed46471cc247c6cacefac890a8472c083 < 943ed56606a7ab2fe5a99cad572dd17d484310c7`
- `Linux >= 78c6e39fef5c428960aff742149bba302dd46f5a < a19b61fdb958ffadbba85b43c991eb9fc70c1c1c`
- `Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab < 0425aaf20b407d2f2cf3bf469808e4a35f9abb8b`
- `Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab < bd435f4b738130d732ef64e0e57e45185f77165d`
- `Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab < 8b08ea9690b212b7bf7f12414039259cf34b1aa0`
- `Linux >= a4e772898f8bf2e7e1cf661a12c60a5612c4afab < 9368d1ee62829b08aa31836b3ca003803caf0b72`
- `Linux 0790b89c7e911003b8c50ae50e3ac7645de1fae9`
- `Linux df77a678c33871a6e4ac5b54a71662f1d702335b`
- `Linux 81c68e218ab883dfa368460a59b674084c0240da`
- `Linux >= 5.10.226 < 5.10.252`
- `Linux >= 5.15.167 < 5.15.202`
- `Linux >= 6.1.110 < 6.1.165`
- `Linux >= 6.6.51 < 6.6.128`
- `Linux >= 4.19.322 < 4.20`
- `Linux >= 5.4.284 < 5.5`
- `Linux >= 6.10.10 < 6.11`
- `Linux 6.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.