CVE-2025-38234
📋 TL;DR
This CVE describes a race condition vulnerability in the Linux kernel's real-time scheduler (sched/rt) that can cause kernel panics and system crashes. It affects Linux systems using the real-time scheduler when tasks are migrated between CPUs, potentially leading to denial of service. All Linux systems with the 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 →⚠️ Risk & Real-World Impact
Worst Case
Complete system crash and kernel panic leading to denial of service, potentially causing data loss or service disruption.
Likely Case
System instability, kernel panics, and crashes under specific real-time scheduling conditions, resulting in denial of service.
If Mitigated
Minimal impact if systems don't heavily use real-time scheduling or have proper monitoring and redundancy.
🎯 Exploit Status
Exploitation requires local access and ability to create real-time tasks that trigger the race condition during CPU migration.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Multiple stable kernel versions with fixes referenced in git commits
Vendor Advisory: https://git.kernel.org/stable/c/07ecabfbca64f4f0b6071cf96e49d162fa9d138d
Restart Required: Yes
Instructions:
1. Identify current kernel version. 2. Check if your distribution has released a patched kernel version. 3. Update kernel package using your distribution's package manager (apt, yum, dnf, etc.). 4. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable real-time scheduling
linuxAvoid using real-time scheduling policies to prevent triggering the race condition
# Limit real-time scheduling via ulimit
ulimit -r 0
# Or configure system-wide limits in /etc/security/limits.conf
CPU affinity restrictions
linuxPin real-time tasks to specific CPUs to reduce migration events
taskset -c 0-3 <command>
# Or use sched_setaffinity() in applications
🧯 If You Can't Patch
- Implement strict access controls to limit who can create real-time processes
- Monitor system logs for kernel panic signatures and implement automated recovery procedures
🔍 How to Verify
Check if Vulnerable:
Check kernel version and compare with patched versions from kernel git commits. Vulnerable if using affected kernel version with real-time scheduling enabled.Check Version:
uname -rVerify Fix Applied:
Verify kernel version after update matches patched version. Monitor system stability under real-time workload.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- BUG: kernel NULL pointer dereference
- BUG: unable to handle page fault
- kernel BUG at kernel/sched/rt.c
- Call traces involving push_rt_task or pick_next_task_rt
Network Indicators:
- None - this is a local kernel vulnerability
SIEM Query:
source="kernel" AND ("BUG:" OR "kernel panic" OR "sched/rt" OR "push_rt_task")