---
id: CVE-2026-64004
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/iucv: fix locking in .getsockopt

  Mirror iucv_sock_setsockopt() and wrap the whole switch in
  lock_sock()/release_sock()
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/iucv: fix locking in .getsockopt

  Mirror iucv_sock_setsockopt() and wrap the whole switch in
  lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock
  beco…
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'
cwe:
  - CWE-667
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.4, < 5.10.259'
  - 'linux_kernel >= 5.11, < 5.15.210'
  - 'linux_kernel >= 5.16, < 6.1.176'
  - 'linux_kernel >= 6.2, < 6.6.143'
  - 'linux_kernel >= 6.7, < 6.12.93'
  - 'linux_kernel >= 6.13, < 6.18.35'
  - 'linux_kernel >= 6.19, < 7.0.12'
  - linux_kernel = 7.1
patched:
  - linux_kernel 7.0.12
published: '2026-07-19'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T18:37:41.130'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64004'
references:
  - url: 'https://git.kernel.org/stable/c/1fc30bd4e55e2dd622d2d366cecd732c1841bbee'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3589d20a666caf30ad100c960a2de7de390fce88'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/45bb8de8c95d8899f4b8f61bd9bceb8132af73cb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/69554adc7a6fa04ede3ad7512321d83748e3c920'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6e792b8dd3002bbc4136745928a9605df1a72b8a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/884eb247b74d86db97e3a37f0d6fc8e1e83590dd'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9817369243380e287ebe5525411557eaa3aa2a79'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cd691beafea0dd779e69e81ccc26b0ab50efcb5e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00129
epssPercentile: 0.02192
ingestedAt: '2026-10-08T18:58:11.293Z'
---

## Overview

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

net/iucv: fix locking in .getsockopt

Mirror iucv_sock_setsockopt() and wrap the whole switch in
lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock
becomes redundant and is removed.

Any AF_IUCV HIPER user can potentially crash the kernel by racing
recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences
iucv->hs_dev->mtu after iucv_sock_close() (called from the racing
recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference
oops.

## Affected

- `linux_kernel >= 3.4, < 5.10.259`
- `linux_kernel >= 5.11, < 5.15.210`
- `linux_kernel >= 5.16, < 6.1.176`
- `linux_kernel >= 6.2, < 6.6.143`
- `linux_kernel >= 6.7, < 6.12.93`
- `linux_kernel >= 6.13, < 6.18.35`
- `linux_kernel >= 6.19, < 7.0.12`
- `linux_kernel = 7.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.12`