CVE-2024-56782
📋 TL;DR
This CVE describes a NULL pointer dereference vulnerability in the Linux kernel's ACPI subsystem. If exploited, it could cause a kernel panic leading to system crash or denial of service. This affects Linux systems using ACPI with specific hardware configurations.
💻 Affected Systems
- Linux kernel
📦 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
Kernel panic leading to system crash, requiring physical or remote console access to reboot the system, causing extended downtime.
Likely Case
System crash or kernel panic when specific ACPI hardware enumeration occurs, requiring reboot to restore functionality.
If Mitigated
Minor system instability or no impact if the vulnerable code path isn't triggered by hardware configuration.
🎯 Exploit Status
Exploitation requires triggering the specific ACPI enumeration path with NULL controller_parent, which may require specific hardware or configuration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel branches (commits 4a49194f587a and e173bce05f703)
Vendor Advisory: https://git.kernel.org/stable/c/4a49194f587a62d972b602e3e1a2c3cfe6567966
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from distribution vendor. 2. Rebuild kernel if using custom kernel. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable ACPI if not needed
linuxAdd kernel boot parameter to disable ACPI subsystem if not required for hardware functionality
Add 'acpi=off' to kernel boot parameters in GRUB configuration
🧯 If You Can't Patch
- Restrict local access to prevent potential triggering by users or processes
- Monitor system logs for kernel panic events and implement rapid response procedures
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if it includes the vulnerable commit. Use 'uname -r' and compare with distribution security advisories.Check Version:
uname -rVerify Fix Applied:
Verify kernel version after update includes the patched commits. Check with 'uname -r' and confirm with distribution security updates.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- System crash/reboot events without clear cause
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kern.log" AND "kernel panic" OR "NULL pointer dereference"