CVE-2024-46870
📋 TL;DR
A race condition vulnerability in the AMD display driver for Linux kernel DCN35 architecture could cause system hangs when DMCUB processes commands slower than expected. This affects Linux systems with AMD graphics hardware using DCN35 display architecture. The vulnerability requires local access to trigger.
💻 Affected Systems
- Linux kernel with AMD display 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 →⚠️ Risk & Real-World Impact
Worst Case
System becomes unresponsive and requires hard reboot, potentially causing data loss or service disruption.
Likely Case
Intermittent display glitches or temporary system freezes during graphics-intensive operations.
If Mitigated
Minor performance impact with diagnostic logging but no system hangs.
🎯 Exploit Status
Exploitation requires triggering specific race condition timing during DMCUB command processing. Not trivial to weaponize.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 31c254c9cd4b122a10db297124f867107a696d83 or 7c70e60fbf4bff1123f0e8d5cb1ae71df6164d7f
Vendor Advisory: https://git.kernel.org/stable/c/31c254c9cd4b122a10db297124f867107a696d83
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Reboot system. 3. Verify kernel version with 'uname -r'.
🔧 Temporary Workarounds
Disable IPS feature
linuxDisable Idle Power Saving feature to prevent the race condition
echo 0 > /sys/class/drm/card*/device/power_dpm_force_performance_level
🧯 If You Can't Patch
- Avoid graphics-intensive applications that may trigger DMCUB timeouts
- Monitor system for display-related hangs and have reboot procedures ready
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if using AMD graphics with DCN35 architecture. Run 'lspci | grep -i amd' and 'uname -r'Check Version:
uname -rVerify Fix Applied:
Verify kernel version contains the fix commit: 'git log --oneline | grep -i "31c254c9cd4b122a10db297124f867107a696d83"'📡 Detection & Monitoring
Log Indicators:
- Kernel logs showing DMCUB timeout errors
- System hang events in system logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("DMCUB" OR "timeout" OR "display")