CVE-2023-52986
📋 TL;DR
A Linux kernel vulnerability in the BPF sockmap subsystem allows improper handling of cloned listening sockets, potentially leading to denial of service. Systems running affected Linux kernel versions with BPF sockmap functionality enabled are vulnerable. This affects servers and devices using BPF for socket redirection or filtering.
💻 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 →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 or system crash due to infinite recursion when closing affected sockets, causing complete denial of service.
Likely Case
System instability, kernel crashes, or service disruption when BPF sockmap operations interact with cloned listening sockets.
If Mitigated
Minimal impact if BPF sockmap functionality is disabled or systems are not using socket cloning with sockmap.
🎯 Exploit Status
Exploitation requires kernel-level access and specific BPF sockmap configurations. The vulnerability was discovered through code review and crash reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits: 12b0ec7c6953e1602957926439e5297095d7d065, 9bd6074e1872d22190a8da30e796cbf937d334f0, c681d7a4ed3d360de0574f4d6b7305a8de8dc54f, ddce1e091757d0259107c6c0c7262df201de2b66
Vendor Advisory: https://git.kernel.org/stable/c/12b0ec7c6953e1602957926439e5297095d7d065
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify kernel version matches patched release.
🔧 Temporary Workarounds
Disable BPF sockmap
linuxPrevent vulnerability by disabling BPF sockmap functionality if not required.
echo 0 > /proc/sys/net/core/bpf_jit_enable
Remove or disable BPF programs using sockmap
🧯 If You Can't Patch
- Avoid using BPF sockmap with listening sockets that may be cloned
- Monitor system logs for kernel crashes or socket-related errors and restart affected services
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if BPF sockmap is in use. Vulnerable if using unpatched kernel with sockmap functionality.Check Version:
uname -rVerify Fix Applied:
Confirm kernel version includes the fix commits and test sockmap operations with socket cloning.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Socket-related kernel errors
- BPF program failures
Network Indicators:
- Unexpected socket closure
- Service disruption on ports using BPF sockmap
SIEM Query:
Search for kernel panic events or socket error messages in system logs