CVE-2023-53581
📋 TL;DR
A race condition vulnerability in the Linux kernel's mlx5e network driver allows concurrent removal of flows from the unready_flows list, leading to a double-removal and kernel crash. This affects systems using Mellanox network adapters with the mlx5 driver. The vulnerability requires local access to trigger via tc (traffic control) commands.
💻 Affected Systems
- Linux kernel mlx5e 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially disrupting network connectivity and requiring physical or remote console access to reboot.
Likely Case
Local denial of service causing system instability or crash when specific tc operations are performed concurrently with flow cleanup.
If Mitigated
Minimal impact if systems are patched or not using affected mlx5 driver configurations.
🎯 Exploit Status
Exploitation requires CAP_NET_ADMIN privileges and concurrent tc operations. No public exploit code has been observed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in Linux kernel stable commits: 30c281a77fb1b2d362030ea243dd663201d62a21, 65e64640e97c0f223e77f9ea69b5a46186b93470, 82ac62d76a000871004f534ad294e763e966d3b0, e962fd5933ebc767ce2a1cf7b7c85035b5a5d04c, f7ceedd1d124217a67ed1a67bbd7a7b1288705e3
Vendor Advisory: https://git.kernel.org/stable/c/30c281a77fb1b2d362030ea243dd663201d62a21
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing fixes. 2. For distributions: Use package manager (apt/yum/dnf) to install latest kernel updates. 3. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable mlx5 driver
linuxUnload mlx5 driver if Mellanox hardware is not required, preventing vulnerability trigger.
sudo modprobe -r mlx5_core
sudo modprobe -r mlx5_ib
sudo modprobe -r mlx5e
Restrict CAP_NET_ADMIN
linuxLimit users and processes with CAP_NET_ADMIN capability to reduce attack surface.
Review /etc/security/capability.conf and user capabilities
Use setcap or capability-aware containers to restrict privileges
🧯 If You Can't Patch
- Monitor system logs for kernel panic indicators related to mlx5e_tc_del_fdb_flow
- Restrict local user access and audit tc command usage on affected systems
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if mlx5 modules are loaded: uname -r && lsmod | grep mlx5Check Version:
uname -rVerify Fix Applied:
Verify kernel version is patched and check dmesg for absence of mlx5e crash reports after update.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages mentioning mlx5e_tc_del_fdb_flow
- General protection fault errors with addresses like 0xdead000000000108 in dmesg
Network Indicators:
- Sudden loss of network connectivity on Mellanox interfaces
SIEM Query:
source="kernel" AND "general protection fault" AND "mlx5"🔗 References
- https://git.kernel.org/stable/c/30c281a77fb1b2d362030ea243dd663201d62a21
- https://git.kernel.org/stable/c/65e64640e97c0f223e77f9ea69b5a46186b93470
- https://git.kernel.org/stable/c/82ac62d76a000871004f534ad294e763e966d3b0
- https://git.kernel.org/stable/c/e962fd5933ebc767ce2a1cf7b7c85035b5a5d04c
- https://git.kernel.org/stable/c/f7ceedd1d124217a67ed1a67bbd7a7b1288705e3
