CVE-2024-43856
📋 TL;DR
A race condition vulnerability in the Linux kernel's DMA memory management subsystem allows a use-after-free scenario when freeing DMA-allocated memory. This affects any system using the dmam_free_coherent() function, primarily impacting devices with DMA capabilities. Attackers could potentially exploit this to cause kernel crashes or memory corruption.
💻 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 →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 →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 leading to system crash, denial of service, or potential privilege escalation if memory corruption leads to arbitrary code execution in kernel context.
Likely Case
System instability, kernel crashes, or denial of service affecting DMA operations on affected devices.
If Mitigated
Minimal impact if systems are patched or don't heavily utilize DMA operations with the affected function.
🎯 Exploit Status
Exploitation requires local access and ability to manipulate DMA memory allocations with specific timing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes referenced in CVE
Vendor Advisory: https://git.kernel.org/stable/c/1fe97f68fce1ba24bf823bfb0eb0956003473130
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable DMA on non-essential devices
linuxReduce attack surface by disabling DMA on devices that don't require it
echo 0 > /sys/class/dma/dma_device/enable
🧯 If You Can't Patch
- Restrict access to DMA-capable devices to trusted users only
- Implement strict process isolation and resource limits to prevent exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions in git commits. Use: uname -r and verify against known vulnerable ranges.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include the fix commits referenced in the CVE.📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- WARN_ON() messages related to dmam_match
- System crash/reboot events
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("WARN_ON" OR "dmam_match" OR "kernel panic")🔗 References
- https://git.kernel.org/stable/c/1fe97f68fce1ba24bf823bfb0eb0956003473130
- https://git.kernel.org/stable/c/22094f5f52e7bc16c5bf9613365049383650b02e
- https://git.kernel.org/stable/c/257193083e8f43907e99ea633820fc2b3bcd24c7
- https://git.kernel.org/stable/c/28e8b7406d3a1f5329a03aa25a43aa28e087cb20
- https://git.kernel.org/stable/c/2f7bbdc744f2e7051d1cb47c8e082162df1923c9
- https://git.kernel.org/stable/c/87b34c8c94e29fa01d744e5147697f592998d954
- https://git.kernel.org/stable/c/f993a4baf6b622232e4c190d34c220179e5d61eb
- https://git.kernel.org/stable/c/fe2d246080f035e0af5793cb79067ba125e4fb63
- https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
