CVE-2024-27079
📋 TL;DR
This vulnerability is a NULL pointer dereference in the Linux kernel's Intel IOMMU driver that can cause kernel crashes during device release operations. It specifically affects systems running in kdump mode where IOMMU uses deferred attachment. The crash leads to denial of service and potential system instability.
💻 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
Complete system crash and denial of service, potentially disrupting critical operations and causing data loss in crash kernel scenarios.
Likely Case
System instability and crashes during device removal operations in kdump kernels, leading to service disruption.
If Mitigated
Minimal impact with proper patching; systems not using kdump or IOMMU deferred attachment are unaffected.
🎯 Exploit Status
Requires local access and ability to trigger device release operations in specific kernel configuration. Not easily weaponized for privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel branches via git commits 333fe86968482ca701c609af590003bcea450e8f and 81e921fd321614c2ad8ac333b041aae1da7a1c6d
Vendor Advisory: https://git.kernel.org/stable/c/333fe86968482ca701c609af590003bcea450e8f
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from distribution vendor. 2. For custom kernels, apply patches from git.kernel.org. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable kdump if not needed
linuxDisable kdump functionality to avoid triggering the vulnerable code path
systemctl disable kdump.service
systemctl stop kdump.service
Disable Intel IOMMU
linuxDisable IOMMU in kernel boot parameters if not required
Edit /etc/default/grub and add 'intel_iommu=off' to GRUB_CMDLINE_LINUX
update-grub
reboot
🧯 If You Can't Patch
- Avoid using kdump functionality on affected systems
- Monitor system logs for kernel crashes and device removal operations
🔍 How to Verify
Check if Vulnerable:
Check if system uses kdump: systemctl status kdump.service. Check kernel version and if Intel IOMMU is enabled: dmesg | grep -i iommuCheck Version:
uname -rVerify Fix Applied:
Verify kernel version after update and check that patches are applied: grep -r 'release_domain' /usr/src/linux/drivers/iommu/intel/📡 Detection & Monitoring
Log Indicators:
- Kernel NULL pointer dereference messages in dmesg or /var/log/kern.log
- Crash reports mentioning intel_iommu_release_device
- Device removal failures
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "intel_iommu_release_device" OR "BUG: kernel")