Skip to content
Fencer Vulns
medium 5.5

CVE-2023-53419 json

rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access

published 2025-09-18 13 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-29880

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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. ]

Patch / fix

  • Linux Linux 5.10.181, 5.15.113, 6.1.30, 6.3.4, 6.4
  • linux Debian 12 6.1.37-1
  • linux Debian 14, Debian 13 6.3.7-1

debian advisories DEBIAN-CVE-2023-53419

  • linux Ubuntu 22.04 LTS 5.15.0-83.92
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1044.49
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1041.49
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1041.46
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1037.40
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1041.46
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1046.53
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1027.32

ubuntu advisories UBUNTU-CVE-2023-53419

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53419 updated cvss 5.5

kernel: rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.