CVE-2022-48892
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's scheduler when duplicating CPU affinity pointers during fork operations. The bug allows potential kernel memory corruption and privilege escalation. All Linux systems with 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic, system crash, or privilege escalation to root via kernel memory corruption leading to arbitrary code execution.
Likely Case
System instability, crashes, or denial of service when specific race conditions occur during process forking and CPU affinity changes.
If Mitigated
Minimal impact if proper kernel hardening and privilege separation are in place, though crashes could still occur.
🎯 Exploit Status
Exploitation requires local access and specific timing conditions between fork() and sched_setaffinity() calls.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in stable kernel releases with commits 7b5cc7fd1789, 87ca4f9efbd7, b22faa21b623
Vendor Advisory: https://git.kernel.org/stable/c/7b5cc7fd1789ea5dbb942c9f8207b076d365badc
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 matches patched release.
🔧 Temporary Workarounds
Restrict CPU affinity modifications
linuxLimit ability to modify CPU affinity through cgroups or permissions
chmod 644 /proc/self/status
cgroup configuration to restrict sched_setaffinity
🧯 If You Can't Patch
- Implement strict privilege separation to limit who can fork processes and modify CPU affinity
- Monitor for system crashes or unusual process behavior that might indicate exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with distribution's security advisories. Vulnerable if between affected commit ranges.Check Version:
uname -rVerify Fix Applied:
Verify kernel version matches patched release from your distribution. Check /proc/version or uname -r.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- System crashes
- Unexpected process terminations
Network Indicators:
- None - local vulnerability only
SIEM Query:
search 'kernel: BUG:' OR 'kernel: Oops:' OR 'kernel: general protection fault' in system logs