---
id: CVE-2026-43215
title: 'cifs: Fix locking usage for tcon fields'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cifs: Fix locking usage for tcon fields

  We used to use the cifs_tcp_ses_lock to protect a lot of objects
  that are not just the server, ses or tcon lists. We later intr…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 <
    953953abb66e52c224057ab91e404284fefeab62
  - >-
    Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 <
    601dd3b79769b38d30b693c40afdb2a4b7edf9d0
  - >-
    Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 <
    3969db6b22e3d90d8c5f22ac1a7fe0350a94c136
  - >-
    Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 <
    8c59eeeeffa1524ef57e173a89a1a3ff539888d5
  - >-
    Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 <
    96c4af418586ee9a6aab61738644366426e05316
  - Linux 6.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:15:53.438726Z'
published: '2026-05-06'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:37.159Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43215'
references:
  - url: 'https://git.kernel.org/stable/c/953953abb66e52c224057ab91e404284fefeab62'
  - url: 'https://git.kernel.org/stable/c/601dd3b79769b38d30b693c40afdb2a4b7edf9d0'
  - url: 'https://git.kernel.org/stable/c/3969db6b22e3d90d8c5f22ac1a7fe0350a94c136'
  - url: 'https://git.kernel.org/stable/c/8c59eeeeffa1524ef57e173a89a1a3ff539888d5'
  - url: 'https://git.kernel.org/stable/c/96c4af418586ee9a6aab61738644366426e05316'
tags:
  - cve.org
epss: 0.00409
epssPercentile: 0.33581
ingestedAt: '2026-10-16T17:24:46.688Z'
---

## Overview

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

cifs: Fix locking usage for tcon fields

We used to use the cifs_tcp_ses_lock to protect a lot of objects
that are not just the server, ses or tcon lists. We later introduced
srv_lock, ses_lock and tc_lock to protect fields within the
corresponding structs. This was done to provide a more granular
protection and avoid unnecessary serialization.

There were still a couple of uses of cifs_tcp_ses_lock to provide
tcon fields. In this patch, I've replaced them with tc_lock.

## Affected

- `Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 < 953953abb66e52c224057ab91e404284fefeab62`
- `Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 < 601dd3b79769b38d30b693c40afdb2a4b7edf9d0`
- `Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 < 3969db6b22e3d90d8c5f22ac1a7fe0350a94c136`
- `Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 < 8c59eeeeffa1524ef57e173a89a1a3ff539888d5`
- `Linux >= d7d7a66aacd6fd8ca57baf08a7bac5421282f6f8 < 96c4af418586ee9a6aab61738644366426e05316`
- `Linux 6.0`

## Remediation

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