CVE-2022-49443
📋 TL;DR
This CVE describes a data race condition in the Linux kernel's epoll subsystem where concurrent access to the rdllist structure without proper synchronization can cause memory corruption. It affects Linux systems using epoll for I/O event notification, potentially leading to kernel crashes or instability. The vulnerability requires local access to exploit.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic or system crash leading to denial of service, potentially allowing privilege escalation if combined with other vulnerabilities.
Likely Case
System instability, application crashes, or denial of service for processes using epoll.
If Mitigated
Minor performance impact from proper locking, no security impact when patched.
🎯 Exploit Status
Exploitation requires local access and the ability to trigger concurrent epoll operations. No public exploits have been reported.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits: 5d5d993f16be15d124be7b8ec71b28ef7b7dc3af, cb3e48f7a35033deb9455abe3932e63cb500b9eb, d679ae94fdd5d3ab00c35078f5af5f37e068b03d, e039c0b5985999b150594126225e1ee51df7b4c9
Vendor Advisory: https://git.kernel.org/stable/c/5d5d993f16be15d124be7b8ec71b28ef7b7dc3af
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check your distribution's security advisories for backported patches. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable epoll optimizations
linuxRevert to using locked ep_events_available() calls by modifying kernel configuration or using kernel parameters if available.
Not applicable via command line - requires kernel recompilation or module parameter if supported
🧯 If You Can't Patch
- Restrict local user access to minimize attack surface
- Monitor system logs for kernel panic or instability indicators
🔍 How to Verify
Check if Vulnerable:
Check kernel version with 'uname -r' and compare against affected versions. Check if epoll is being used by monitoring processes.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits or is newer than affected versions. Check system stability during epoll-intensive operations.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- System crash dumps
- Application crashes related to epoll operations
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "BUG") AND process="epoll"