CVE-2022-49995
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's writeback subsystem when a storage device is removed. Attackers could potentially exploit this to cause kernel crashes or execute arbitrary code with kernel privileges. All Linux systems using affected kernel versions are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash or potential arbitrary code execution with kernel privileges, resulting in complete system compromise.
Likely Case
System instability, kernel crashes, or denial of service when storage devices are removed or fail during operation.
If Mitigated
System remains stable with proper patching; unpatched systems risk crashes during storage operations.
🎯 Exploit Status
Exploitation requires triggering specific timing conditions during storage device removal and may require local access
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7, f87904c075515f3e1d8f4a7115869d3b914674fd, f96b9f7c1676923bce871e728bb49c0dfa5013cc
Vendor Advisory: https://git.kernel.org/stable/c/9a6c710f3bc10bc9cc23e1c080b53245b7f9d5b7
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable hot-plug storage removal
linuxPrevent storage devices from being removed while system is running to avoid triggering the vulnerability
echo 0 > /sys/block/[device]/device/delete
echo 0 > /sys/block/[device]/device/remove
🧯 If You Can't Patch
- Restrict physical and logical access to storage devices to prevent unauthorized removal
- Implement monitoring for storage device removal events and system crashes
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution's security advisories for affected versionsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched version from vendor advisory and check for presence of fix commits📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Storage device removal events in system logs
- Unexpected system crashes
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
Search for kernel panic events or storage device removal logs followed by system instability