CVE-2024-56538
📋 TL;DR
This Linux kernel vulnerability in the ZynqMP KMS driver allows use-after-free conditions when userspace accesses a DRM device during removal. Attackers could potentially crash the system or execute arbitrary code. Systems using affected Linux kernel versions with the zynqmp_kms driver are vulnerable.
💻 Affected Systems
- Linux kernel with zynqmp_kms 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 →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, system crash, or potential arbitrary code execution with kernel privileges leading to complete system compromise.
Likely Case
System instability, crashes, or denial of service affecting graphical functionality.
If Mitigated
Userspace applications receive errors when accessing the device but no memory corruption occurs.
🎯 Exploit Status
Exploitation requires local access and knowledge of DRM subsystem interactions. The vulnerability is in device removal handling.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commits 2e07c88914fc5289c21820b1aa94f058feb38197, 4fb97432e28a7e136b2d76135d50e988ada8e1af, 692f52aedccbf79b212a1e14e3735192b4c24a7d, a17b9afe58c474657449cf87e238b1788200576b
Vendor Advisory: https://git.kernel.org/stable/c/2e07c88914fc5289c21820b1aa94f058feb38197
Restart Required: Yes
Instructions:
1. Update to a patched Linux kernel version from your distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the kernel version after reboot.
🔧 Temporary Workarounds
Disable zynqmp_kms module
linuxPrevent loading of the vulnerable kernel module if not required
echo 'blacklist zynqmp_kms' >> /etc/modprobe.d/blacklist.conf
rmmod zynqmp_kms
🧯 If You Can't Patch
- Restrict local user access to systems using the vulnerable driver
- Monitor system logs for crashes or unusual DRM-related activity
🔍 How to Verify
Check if Vulnerable:
Check if zynqmp_kms module is loaded: lsmod | grep zynqmp_kms. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits. Check that zynqmp_kms module functions normally without crashes.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- DRM subsystem errors
- System crashes during graphics operations
SIEM Query:
source="kernel" AND ("zynqmp_kms" OR "DRM" OR "use-after-free")