CVE-2024-38555
📋 TL;DR
This CVE-2024-38555 is a use-after-free vulnerability in the Linux kernel's mlx5 network driver that occurs when firmware command completions arrive while the device is in an internal error state. If exploited, it could lead to kernel memory corruption, system crashes, or potential privilege escalation. This affects systems using Mellanox network adapters with the mlx5 driver.
💻 Affected Systems
- Linux kernel mlx5 network 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 →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, potential privilege escalation to root, or remote code execution if combined with other vulnerabilities.
Likely Case
System instability, kernel crashes, denial of service affecting network connectivity and system availability.
If Mitigated
Limited to denial of service on affected network interfaces with proper isolation and monitoring.
🎯 Exploit Status
Exploitation requires ability to induce device internal errors through network traffic or other means.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 1337ec94bc5a9eed250e33f5f5c89a28a6bfabdb, 1d5dce5e92a70274de67a59e1e674c3267f94cd7, 3cb92b0ad73d3f1734e812054e698d655e9581b0, 7ac4c69c34240c6de820492c0a28a0bd1494265a, bf8aaf0ae01c27ae3c06aa8610caf91e50393396
Vendor Advisory: https://git.kernel.org/stable/c/1337ec94bc5a9eed250e33f5f5c89a28a6bfabdb
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check distribution-specific security advisories. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable mlx5 driver
linuxTemporarily disable the vulnerable mlx5 driver if Mellanox networking is not critical
modprobe -r mlx5_core
echo 'blacklist mlx5_core' > /etc/modprobe.d/disable-mlx5.conf
Network isolation
allIsolate systems with mlx5 devices from untrusted networks
🧯 If You Can't Patch
- Implement strict network segmentation to limit exposure to potential exploit traffic
- Monitor kernel logs for refcount warnings and mlx5 error messages
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if mlx5 driver is loaded: lsmod | grep mlx5Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits and check dmesg for absence of refcount warnings related to mlx5📡 Detection & Monitoring
Log Indicators:
- refcount_t: underflow; use-after-free warnings
- mlx5_core error messages
- kernel panic logs
Network Indicators:
- Unusual network patterns causing device errors
- Increased packet loss on mlx5 interfaces
SIEM Query:
source="kernel" AND ("refcount_t: underflow" OR "mlx5_cmd_comp_handler" OR "use-after-free")🔗 References
- https://git.kernel.org/stable/c/1337ec94bc5a9eed250e33f5f5c89a28a6bfabdb
- https://git.kernel.org/stable/c/1d5dce5e92a70274de67a59e1e674c3267f94cd7
- https://git.kernel.org/stable/c/3cb92b0ad73d3f1734e812054e698d655e9581b0
- https://git.kernel.org/stable/c/7ac4c69c34240c6de820492c0a28a0bd1494265a
- https://git.kernel.org/stable/c/bf8aaf0ae01c27ae3c06aa8610caf91e50393396
- https://git.kernel.org/stable/c/db9b31aa9bc56ff0d15b78f7e827d61c4a096e40
- https://git.kernel.org/stable/c/f6fbb8535e990f844371086ab2c1221f71f993d3
- https://git.kernel.org/stable/c/1337ec94bc5a9eed250e33f5f5c89a28a6bfabdb
- https://git.kernel.org/stable/c/1d5dce5e92a70274de67a59e1e674c3267f94cd7
- https://git.kernel.org/stable/c/3cb92b0ad73d3f1734e812054e698d655e9581b0
- https://git.kernel.org/stable/c/7ac4c69c34240c6de820492c0a28a0bd1494265a
- https://git.kernel.org/stable/c/bf8aaf0ae01c27ae3c06aa8610caf91e50393396
- https://git.kernel.org/stable/c/db9b31aa9bc56ff0d15b78f7e827d61c4a096e40
- https://git.kernel.org/stable/c/f6fbb8535e990f844371086ab2c1221f71f993d3
