CVE-2024-39479
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's i915 graphics driver hardware monitoring (hwmon) component. The vulnerability occurs during device unbind operations when hardware monitoring resources are accessed after their dependent data structures have been freed, potentially leading to kernel crashes or privilege escalation. This affects systems using Intel integrated graphics with the i915 driver.
💻 Affected Systems
- Linux kernel with i915 graphics driver
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, or potential privilege escalation to kernel mode allowing full system compromise.
Likely Case
System instability, kernel crashes, or denial of service when graphics hardware is being unbound/removed.
If Mitigated
No impact if patched or if vulnerable code paths aren't triggered during normal operation.
🎯 Exploit Status
Requires local access and ability to trigger device unbind operations. Race condition makes exploitation timing-sensitive.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits 5bc9de065b8bb9b8dd8799ecb4592d0403b54281 and related fixes
Vendor Advisory: https://git.kernel.org/stable/c/5bc9de065b8bb9b8dd8799ecb4592d0403b54281
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify i915 driver is loaded and functioning.
🔧 Temporary Workarounds
Disable i915 hwmon module
linuxPrevent loading of the vulnerable hwmon component
echo 'blacklist i915_hwmon' >> /etc/modprobe.d/blacklist-i915-hwmon.conf
update-initramfs -u
reboot
Restrict device unbind operations
linuxLimit ability to trigger vulnerable code path
chmod 644 /sys/bus/pci/drivers/i915/unbind
chown root:root /sys/bus/pci/drivers/i915/unbind
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable kernels
- Monitor for kernel crashes or unusual graphics driver behavior
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if i915 driver is loaded: 'uname -r' and 'lsmod | grep i915'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check dmesg for i915 driver loading without errors📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- i915 driver errors in dmesg
- Use-after-free warnings in kernel logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("i915" OR "use-after-free" OR "UAF")🔗 References
- https://git.kernel.org/stable/c/5bc9de065b8bb9b8dd8799ecb4592d0403b54281
- https://git.kernel.org/stable/c/ce5a22d22db691d14516c3b8fdbf69139eb2ea8f
- https://git.kernel.org/stable/c/cfa73607eb21a4ce1d6294a2c5733628897b48a2
- https://git.kernel.org/stable/c/5bc9de065b8bb9b8dd8799ecb4592d0403b54281
- https://git.kernel.org/stable/c/ce5a22d22db691d14516c3b8fdbf69139eb2ea8f
- https://git.kernel.org/stable/c/cfa73607eb21a4ce1d6294a2c5733628897b48a2
