<p>Upgrade <code>AlmaLinux:9</code> <code>kernel-64k-debug</code> to version 0:5.14.0-427.31.1.el9_4 or higher.<br>This issue was patched in <code>ALSA-2024:5363</code>.</p>

NULL Pointer Dereference Affecting kernel-64k-debug package, versions <0:5.14.0-427.31.1.el9_4

Threat Intelligence

0.04% (6^th percentile)

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Snyk ID SNYK-ALMALINUX9-KERNEL64KDEBUG-8331951
published 4 Nov 2024
disclosed 14 Aug 2024

Report a new vulnerability Found a mistake?

Introduced: 14 Aug 2024

CVE-2024-36489 Open this link in a new tab CWE-476 Open this link in a new tab

How to fix?

Upgrade AlmaLinux:9 kernel-64k-debug to version 0:5.14.0-427.31.1.el9_4 or higher.
This issue was patched in ALSA-2024:5363.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-64k-debug package and not the kernel-64k-debug package as distributed by AlmaLinux. See How to fix? for AlmaLinux:9 relevant fixed versions and status.

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-&gt;sk_prot)-&gt;setsockopt()

                           // In tls_{setsockopt,getsockopt}()
                           ctx-&amp;gt;sk_proto-&amp;gt;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.

References

CVSS Scores

version 3.1

Attack Vector (AV)

Local
Attack Complexity (AC)

Low
Privileges Required (PR)

Low
User Interaction (UI)

None

Scope (S)

Unchanged

Confidentiality (C)

None
Integrity (I)

None
Availability (A)

High

NULL Pointer Dereference Affecting kernel-64k-debug package, versions <0:5.14.0-427.31.1.el9_4

Severity

Based on AlmaLinux security rating