CVE-2023-53419 – This CVE describes a race condition vulnerabili... (How to Fix)

Q: What is the severity of CVE-2023-53419?

CVE-2023-53419 has a CVSS score of 5.5 (MEDIUM). This CVE describes a race condition vulnerability in the Linux kernel's RCU (Read-Copy-Update) subsystem that can lead to a NULL pointer dereference. It affects systems running Linux kernels with CONFIG_PREEMPT_RCU=y configuration, potentially causing kernel panics or system crashes. The vulnerability requires local access to exploit.

📋 TL;DR

This CVE describes a race condition vulnerability in the Linux kernel's RCU (Read-Copy-Update) subsystem that can lead to a NULL pointer dereference. It affects systems running Linux kernels with CONFIG_PREEMPT_RCU=y configuration, potentially causing kernel panics or system crashes. The vulnerability requires local access to exploit.

💻 Affected Systems

Products:

Linux Kernel

Versions: Specific affected versions not explicitly listed in CVE, but patches available for multiple stable branches

Operating Systems: Linux distributions using vulnerable kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects kernels built with CONFIG_PREEMPT_RCU=y configuration. Many production kernels use this configuration for real-time performance.

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic leading to system crash and denial of service, potentially causing data loss or system instability.

🟠

Likely Case

System crash or kernel panic resulting in denial of service, requiring system reboot to restore functionality.

🟢

If Mitigated

No impact if patched or if CONFIG_PREEMPT_RCU is disabled.

🌐 Internet-Facing: LOW - Requires local access to exploit, not remotely exploitable.

🏢 Internal Only: MEDIUM - Local attackers or malicious processes could crash the system, affecting availability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and precise timing to trigger the race condition. No known public exploits.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Multiple stable kernel versions with commits: 2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2, 3c1566bca3f8349f12b75d0a2d5e4a20ad6262ec, a7d21b8585894e6fff973f6ddae42f02b13f600f, d0a8c0e31a09ec1efd53079083e2a677956b4d91, e30a55e98ae6c44253d8b129efefd5da5bc6e3bc

Vendor Advisory: https://git.kernel.org/stable/c/2bc0ae94ef1f9ed322d8ee439de3239ea3632ab2

Restart Required: Yes

Instructions:

1. Update to patched kernel version from your distribution vendor. 2. Rebuild kernel if using custom kernel. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable CONFIG_PREEMPT_RCU

all

Rebuild kernel without CONFIG_PREEMPT_RCU=y configuration option

make menuconfig (navigate to Kernel Features -> Preemption Model -> select option without PREEMPT_RCU)
make
make modules_install
make install

🧯 If You Can't Patch

Restrict local user access to minimize attack surface
Implement strict process isolation and resource limits

🔍 How to Verify

Check if Vulnerable:

Check kernel version and CONFIG_PREEMPT_RCU setting: cat /proc/config.gz | gunzip | grep CONFIG_PREEMPT_RCU

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is patched: uname -r and check against distribution security advisories

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in /var/log/kern.log or dmesg
NULL pointer dereference errors in kernel logs
System crash/reboot events

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("NULL pointer dereference" OR "kernel panic" OR "rcu_print_task_exp_stall")

📊 Metadata

CVE ID: CVE-2023-53419

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-476

EPSS Score: 0.01% exploit probability (1.2th percentile)

Published: September 18, 2025

Last Updated: January 14, 2026

🔗 References

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