CVE-2022-49888 – This CVE describes a kernel stack overflow vuln... (How to Fix)

Q: What is the severity of CVE-2022-49888?

CVE-2022-49888 has a CVSS score of 7.8 (HIGH). This CVE describes a kernel stack overflow vulnerability in the Linux kernel on ARM64 systems with Cortex-A76 CPUs. When the cortex_a76_erratum_1463225_debug_handler() function is probed via kprobes, it can cause recursive exceptions leading to kernel panic and denial of service. This affects Linux systems running on affected ARM64 hardware.

📋 TL;DR

This CVE describes a kernel stack overflow vulnerability in the Linux kernel on ARM64 systems with Cortex-A76 CPUs. When the cortex_a76_erratum_1463225_debug_handler() function is probed via kprobes, it can cause recursive exceptions leading to kernel panic and denial of service. This affects Linux systems running on affected ARM64 hardware.

💻 Affected Systems

Products:

Linux kernel

Versions: Linux kernel versions between commit 6459b8469753e9fe and the fix commits (specific versions vary by distribution)

Operating Systems: Linux distributions running on ARM64 with Cortex-A76 CPUs

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when kprobes are enabled and used on affected ARM64 hardware. Most systems don't use kprobes by default.

📦 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 →

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 service disruption.

🟠

Likely Case

System crash and denial of service when kprobes are used on vulnerable systems, requiring reboot to restore functionality.

🟢

If Mitigated

No impact if kprobes are disabled or the system is not using affected ARM64 hardware.

🌐 Internet-Facing: LOW - Requires local access or ability to load kernel modules/probes.

🏢 Internal Only: MEDIUM - Could be exploited by users with sufficient privileges to use kprobes or by malicious kernel modules.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

The vulnerability demonstration shows how to trigger it via kprobes. Exploitation requires ability to load kprobes (typically root or CAP_SYS_ADMIN).

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel commits: 024f4b2e1f874934943eb2d3d288ebc52c79f55c, 71d6c33fe223255f4416a01514da2c0bc3e283e7, db66629d43b2d12cb43b004a4ca6be1d03228e97

Vendor Advisory: https://git.kernel.org/stable/c/024f4b2e1f874934943eb2d3d288ebc52c79f55c

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. Check your distribution's security advisories for specific patched versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable kprobes

linux

Prevent exploitation by disabling kprobes functionality

echo 0 > /sys/kernel/debug/tracing/events/kprobes/enable
rmmod kprobes if loaded as module

Restrict kprobes usage

linux

Limit which users can use kprobes via capabilities

setcap -r /sys/kernel/debug/tracing/kprobe_events
chmod 600 /sys/kernel/debug/tracing/kprobe_events

🧯 If You Can't Patch

Disable kprobes functionality entirely
Restrict access to debugfs and kprobes to trusted users only

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if running on ARM64 Cortex-A76 hardware. Check if kprobes are enabled: cat /sys/kernel/debug/tracing/events/kprobes/enable

Check Version:

uname -r

Verify Fix Applied:

Check kernel version contains fix commits or is newer than vulnerable range. Test kprobes functionality to ensure no recursion occurs.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages mentioning stack overflow
Recursive exception traces in kernel logs
Multiple 'cortex_a76_erratum_1463225_debug_handler' entries in stack traces

Network Indicators:

Sudden service unavailability without network cause

SIEM Query:

source="kernel" AND ("stack overflow" OR "Kernel panic" OR "cortex_a76_erratum")

📊 Metadata

CVE ID: CVE-2022-49888

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-787

EPSS Score: 0.02% exploit probability (4.5th percentile)

Published: May 1, 2025

Last Updated: May 7, 2025

🔗 References

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