---
id: CVE-2024-36489
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tls: fix missing memory barrier in tls_init

  In tls_init(), a write memory barrier is missing, and store-store
  reordering may cause NULL dereference in tls_{setsockopt,…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tls: fix missing memory barrier in tls_init

  In tls_init(), a write memory barrier is missing, and store-store
  reordering may cause NULL dereference in tls_{setsockopt,…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.7, < 5.10.219'
  - 'linux_kernel >= 5.11, < 5.15.161'
  - 'linux_kernel >= 5.16, < 6.1.93'
  - 'linux_kernel >= 6.2, < 6.6.33'
  - 'linux_kernel >= 6.7, < 6.9.4'
patched:
  - linux_kernel 6.9.4
published: '2024-06-21'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:18:23.000'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-36489'
references:
  - url: 'https://git.kernel.org/stable/c/2c260a24cf1c4d30ea3646124f766ee46169280b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/335c8f1566d8e44c384d16b450a18554896d4e8b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/91e61dd7a0af660408e87372d8330ceb218be302'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ab67c2fd3d070a21914d0c31319d3858ab4e199c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d72e126e9a36d3d33889829df8fc90100bb0e071'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ef21007a7b581c7fe64d5a10c320880a033c837b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2c260a24cf1c4d30ea3646124f766ee46169280b'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/335c8f1566d8e44c384d16b450a18554896d4e8b'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/91e61dd7a0af660408e87372d8330ceb218be302'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/ab67c2fd3d070a21914d0c31319d3858ab4e199c'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/d72e126e9a36d3d33889829df8fc90100bb0e071'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/ef21007a7b581c7fe64d5a10c320880a033c837b'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-613116.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00255
epssPercentile: 0.15939
ingestedAt: '2026-10-15T03:30:12.711Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-09-10T17:09:28.291219Z'
---

## Overview

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

tls: fix missing memory barrier in tls_init

In tls_init(), a write memory barrier is missing, and store-store
reordering may cause NULL dereference in tls_{setsockopt,getsockopt}.

CPU0                               CPU1
-----                              -----
// In tls_init()
// In tls_ctx_create()
ctx = kzalloc()
ctx->sk_proto = READ_ONCE(sk->sk_prot) -(1)

// In update_sk_prot()
WRITE_ONCE(sk->sk_prot, tls_prots)     -(2)

                                   // In sock_common_setsockopt()
                                   READ_ONCE(sk->sk_prot)->setsockopt()

                                   // In tls_{setsockopt,getsockopt}()
                                   ctx->sk_proto->setsockopt()    -(3)

In the above scenario, when (1) and (2) are reordered, (3) can observe
the NULL value of ctx->sk_proto, causing NULL dereference.

To fix it, we rely on rcu_assign_pointer() which implies the release
barrier semantic. By moving rcu_assign_pointer() after ctx->sk_proto is
initialized, we can ensure that ctx->sk_proto are visible when
changing sk->sk_prot.

## Affected

- `linux_kernel >= 5.7, < 5.10.219`
- `linux_kernel >= 5.11, < 5.15.161`
- `linux_kernel >= 5.16, < 6.1.93`
- `linux_kernel >= 6.2, < 6.6.33`
- `linux_kernel >= 6.7, < 6.9.4`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.9.4`