CVE-2022-48754
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's phylib subsystem. The vulnerability occurs when the kernel attempts to reset a network PHY device after it has already been freed, potentially allowing attackers to execute arbitrary code or crash the system. This affects all Linux systems using the affected kernel versions with network interfaces that utilize the phylib subsystem.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to arbitrary code execution with kernel privileges, system crashes, or complete system compromise.
Likely Case
Kernel panic or system crash resulting in denial of service, potentially requiring physical access or reboot to restore functionality.
If Mitigated
No impact if patched or if the specific code path isn't triggered during normal operation.
🎯 Exploit Status
Exploitation requires triggering the specific code path during network device detachment, which typically requires local access or ability to manipulate network interfaces.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 67d271760b037ce0806d687ee6057edc8afd4205, aefaccd19379d6c4620269a162bfb88ff687f289, bd024e36f68174b1793906c39ca16cee0c9295c2, cb2fab10fc5e7a3aa1bb0a68a3abdcf3e37852af, cbda1b16687580d5beee38273f6241ae3725960c
Vendor Advisory: https://git.kernel.org/stable/c/67d271760b037ce0806d687ee6057edc8afd4205
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the fix is applied by checking kernel version.
🔧 Temporary Workarounds
Avoid network device hot-unplug
linuxPrevent triggering the vulnerable code path by avoiding dynamic network device removal
🧯 If You Can't Patch
- Restrict local access to prevent potential privilege escalation attempts
- Monitor system logs for kernel panics or unexpected network device detachment events
🔍 How to Verify
Check if Vulnerable:
Check kernel version against affected ranges and verify if phylib subsystem is present: 'uname -r' and check if system uses network devices with PHY supportCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is newer than the fix commits: 'uname -r' and compare with distribution's patched versions📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Use-after-free kernel warnings
- Network device detachment errors in dmesg
Network Indicators:
- Unexpected network interface disconnections
SIEM Query:
search 'kernel panic' OR 'use-after-free' OR 'BUG:' in system logs🔗 References
- https://git.kernel.org/stable/c/67d271760b037ce0806d687ee6057edc8afd4205
- https://git.kernel.org/stable/c/aefaccd19379d6c4620269a162bfb88ff687f289
- https://git.kernel.org/stable/c/bd024e36f68174b1793906c39ca16cee0c9295c2
- https://git.kernel.org/stable/c/cb2fab10fc5e7a3aa1bb0a68a3abdcf3e37852af
- https://git.kernel.org/stable/c/cbda1b16687580d5beee38273f6241ae3725960c
- https://git.kernel.org/stable/c/f39027cbada43b33566c312e6be3db654ca3ad17
- https://git.kernel.org/stable/c/67d271760b037ce0806d687ee6057edc8afd4205
- https://git.kernel.org/stable/c/aefaccd19379d6c4620269a162bfb88ff687f289
- https://git.kernel.org/stable/c/bd024e36f68174b1793906c39ca16cee0c9295c2
- https://git.kernel.org/stable/c/cb2fab10fc5e7a3aa1bb0a68a3abdcf3e37852af
- https://git.kernel.org/stable/c/cbda1b16687580d5beee38273f6241ae3725960c
- https://git.kernel.org/stable/c/f39027cbada43b33566c312e6be3db654ca3ad17
