CVE-2024-46776
📋 TL;DR
This CVE fixes a NULL pointer dereference vulnerability in the AMD display driver component of the Linux kernel. The vulnerability occurs when DC_LOG_DC logging runs before checking if link->link_enc is NULL, potentially causing kernel crashes or denial of service. Systems using affected AMD graphics hardware with vulnerable kernel versions are affected.
💻 Affected Systems
- Linux kernel with AMD display driver (drm/amd/display)
📦 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 and denial of service, potentially causing data loss or system instability.
Likely Case
System crash or instability when specific display operations are performed with certain AMD graphics configurations.
If Mitigated
Minor system instability that may require reboot, but no privilege escalation or data compromise.
🎯 Exploit Status
Exploitation requires local access and specific conditions to trigger the NULL pointer dereference.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 3a82f62b0d9d7687eac47603bb6cd14a50fa718b, 874e3bb302f97b94ac548959ec4f925b8e7b45e2, or adc74d25cdbba978afbb57caec23bbcd0329f7b8
Vendor Advisory: https://git.kernel.org/stable/c/3a82f62b0d9d7687eac47603bb6cd14a50fa718b
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable AMD display driver
linuxPrevent loading of the vulnerable drm/amd/display module
echo 'blacklist amdgpu' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
🧯 If You Can't Patch
- Restrict local user access to systems with vulnerable kernels
- Monitor system logs for kernel panic or crash events related to display operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if AMD display driver is loaded: lsmod | grep amdgpu && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: git log --oneline | grep -E '3a82f62b0d9d|874e3bb302f9|adc74d25cdbb'📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- NULL pointer dereference errors in dmesg
- System crash reports
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer" OR "kernel panic" OR "Oops")