CVE-2024-36489: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Linux Linux Kernel: from 5.7, before 5.10.219 (fixed in 5.10.219); from 5.11, before 5.15.161 (fixed in 5.15.161); from 5.16, before 6.1.93 (fixed in 6.1.93); from 6.2, before 6.6.33 (fixed in 6.6.33); from 6.7, before 6.9.4 (fixed in 6.9.4)

Published 2024-06-21. Last modified 2026-06-17.