NULL Pointer Dereference Affecting kernel-64k-debug-modules-internal package, versions *


Severity

Recommended
low

Based on CentOS security rating.

Threat Intelligence

EPSS
0.03% (7th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about NULL Pointer Dereference vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-CENTOS9-KERNEL64KDEBUGMODULESINTERNAL-12944343
  • published19 Sept 2025
  • disclosed18 Sept 2025

Introduced: 18 Sep 2025

CVE-2023-53419  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

There is no fixed version for Centos:9 kernel-64k-debug-modules-internal.

NVD Description

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

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

rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access

For kernels built with CONFIG_PREEMPT_RCU=y, the following scenario can result in a NULL-pointer dereference:

       CPU1                                           CPU2

rcu_preempt_deferred_qs_irqrestore rcu_print_task_exp_stall if (special.b.blocked) READ_ONCE(rnp->exp_tasks) != NULL raw_spin_lock_rcu_node np = rcu_next_node_entry(t, rnp) if (&t->rcu_node_entry == rnp->exp_tasks) WRITE_ONCE(rnp->exp_tasks, np) .... raw_spin_unlock_irqrestore_rcu_node raw_spin_lock_irqsave_rcu_node t = list_entry(rnp->exp_tasks->prev, struct task_struct, rcu_node_entry) (if rnp->exp_tasks is NULL, this will dereference a NULL pointer)

The problem is that CPU2 accesses the rcu_node structure's->exp_tasks field without holding the rcu_node structure's ->lock and CPU2 did not observe CPU1's change to rcu_node structure's ->exp_tasks in time. Therefore, if CPU1 sets rcu_node structure's->exp_tasks pointer to NULL, then CPU2 might dereference that NULL pointer.

This commit therefore holds the rcu_node structure's ->lock while accessing that structure's->exp_tasks field.

[ paulmck: Apply Frederic Weisbecker feedback. ]

CVSS Base Scores

version 3.1