CVE-2024-26939 – This is a use-after-free vulnerability in the L... (How to Fix)

Q: What is the severity of CVE-2024-26939?

CVE-2024-26939 has a CVSS score of 7.0 (HIGH). This is a use-after-free vulnerability in the Linux kernel's i915 graphics driver that occurs when destroying virtual memory areas (VMAs) while they're still being retired. It allows attackers with local access to potentially crash the system or execute arbitrary code. Affects systems running vulnerable Linux kernel versions with Intel integrated graphics.

📋 TL;DR

This is a use-after-free vulnerability in the Linux kernel's i915 graphics driver that occurs when destroying virtual memory areas (VMAs) while they're still being retired. It allows attackers with local access to potentially crash the system or execute arbitrary code. Affects systems running vulnerable Linux kernel versions with Intel integrated graphics.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions with commit d93939730347 to before fixes (specific versions vary by distribution)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects systems with Intel integrated graphics (i915 driver). Requires CONFIG_DRM_I915 kernel configuration.

📦 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

Local privilege escalation to kernel-level code execution, potentially leading to full system compromise.

🟠

Likely Case

Kernel panic or system crash causing denial of service.

🟢

If Mitigated

Limited to denial of service if exploit attempts are detected and blocked.

🌐 Internet-Facing: LOW - Requires local access to exploit.

🏢 Internal Only: MEDIUM - Local users or compromised accounts could exploit this vulnerability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and knowledge of kernel exploitation techniques. Race condition makes reliable exploitation challenging.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel commits: 0e45882ca829b26b915162e8e86dbb1095768e9e, 59b2626dd8c8a2e13f18054b3530e0c00073d79f, 5e3eb862df9f972ab677fb19e0d4b9b1be8db7b5, 704edc9252f4988ae1ad7dafa23d0db8d90d7190

Vendor Advisory: https://git.kernel.org/stable/c/0e45882ca829b26b915162e8e86dbb1095768e9e

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing fixes. 2. For distributions: Apply security updates from your vendor. 3. Reboot system to load new kernel.

🔧 Temporary Workarounds

Disable i915 graphics driver

linux

Prevents exploitation by disabling the vulnerable driver (not practical for most systems)

echo 'blacklist i915' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot

🧯 If You Can't Patch

Restrict local user access to systems with Intel graphics
Implement strict privilege separation and limit user capabilities

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if i915 module is loaded: uname -r && lsmod | grep i915

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is updated and check dmesg for absence of VMA-related warnings

📡 Detection & Monitoring

Log Indicators:

ODEBUG warnings about free active objects
Kernel panic messages related to i915_vma or i915_active
WARNING: CPU: PID: at lib/debugobjects.c

Network Indicators:

None - local vulnerability only

SIEM Query:

source="kernel" AND ("ODEBUG" OR "i915_vma" OR "debug_object_free" OR "i915_active_fini")

📊 Metadata

CVE ID: CVE-2024-26939

CVSS v3 Score: 7.0 (HIGH)

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

CWE: CWE-416

Published: May 1, 2024

Last Updated: April 8, 2025

🔗 References

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🔗 Related Vulnerabilities

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