CVE-2022-48809

5.5 MEDIUM

📋 TL;DR

This CVE describes a memory leak vulnerability in the Linux kernel's networking subsystem. When uncloning socket buffer (skb) destination metadata, an incorrect reference count leads to memory that is never freed. This affects all Linux systems using the vulnerable kernel versions.

💻 Affected Systems

Products:
  • Linux kernel
Versions: Specific vulnerable kernel versions not specified in CVE, but patches available for stable branches
Operating Systems: All Linux distributions using vulnerable kernel versions
Default Config Vulnerable: ⚠️ Yes
Notes: Vulnerability is in core networking code, so most Linux configurations are affected if using vulnerable kernel versions.

📦 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

Sustained exploitation could lead to kernel memory exhaustion, causing system instability, denial of service, or potential kernel crashes.

🟠

Likely Case

Gradual memory consumption over time leading to performance degradation and eventual system instability or crashes under high network load.

🟢

If Mitigated

With proper monitoring and memory limits, impact is limited to performance degradation rather than complete system failure.

🌐 Internet-Facing: MEDIUM - Systems processing high volumes of network traffic (servers, routers) are more vulnerable to memory exhaustion.
🏢 Internal Only: LOW - Internal systems with lower network traffic would experience slower memory leak accumulation.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ⚠️ Yes
Complexity: MEDIUM

Exploitation requires generating specific network conditions to trigger the uncloning behavior repeatedly.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patches available in stable kernel branches (commits referenced in CVE)

Vendor Advisory: https://git.kernel.org/stable/c/00e6d6c3bc14dfe32824e2c515f0e0f2d6ecf2f1

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution's repositories. 2. Reboot system to load new kernel.

🔧 Temporary Workarounds

Network traffic limiting

linux

Reduce network traffic that triggers skb uncloning to slow memory leak

🧯 If You Can't Patch

  • Implement aggressive memory monitoring and alerting for kernel memory usage
  • Schedule regular system reboots to clear accumulated memory leaks

🔍 How to Verify

Check if Vulnerable:

Check kernel version against distribution's security advisories for affected versions

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version matches patched version from distribution

📡 Detection & Monitoring

Log Indicators:

  • Kernel oom-killer messages
  • System memory exhaustion warnings
  • Network subsystem errors

Network Indicators:

  • Unusual network traffic patterns triggering skb operations

SIEM Query:

kernel: *oom* OR kernel: *memory* AND (panic OR error)

🔗 References

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