CVE-2025-38106
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's io_uring subsystem. When the __io_uring_show_fdinfo() function accesses freed memory, it can lead to kernel crashes or potential privilege escalation. Any Linux system using io_uring with affected kernel versions is 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, or potential privilege escalation to root if an attacker can control the freed memory region.
Likely Case
System instability, kernel crashes, or denial of service when io_uring operations are performed.
If Mitigated
Limited to denial of service if proper kernel hardening and isolation are in place.
🎯 Exploit Status
Requires local access and ability to trigger io_uring operations. The vulnerability was discovered through syzbot fuzzing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in kernel commits: ac0b8b327a5677dc6fecdf353d808161525b1ff0, af8c13f9ee040b9a287ba246cf0055f7c77b7cc8, d0932758a0a77b38ba1b39564f3b7aba12407061
Vendor Advisory: https://git.kernel.org/stable/c/ac0b8b327a5677dc6fecdf353d808161525b1ff0
Restart Required: Yes
Instructions:
1. Update to a patched kernel version from your distribution vendor. 2. Reboot the system to load the new kernel. 3. Verify the kernel version after reboot.
🔧 Temporary Workarounds
Disable io_uring
linuxRemove io_uring support from the kernel to prevent exploitation
echo 'blacklist io_uring' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict access to io_uring operations using capabilities or SELinux/AppArmor policies
- Monitor system logs for kernel crashes or suspicious io_uring activity
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if io_uring is enabled: 'uname -r' and 'lsmod | grep io_uring'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to a patched version and check for the specific commit hash in kernel source📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- KASAN reports of use-after-free
- System crashes related to io_uring
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
search 'kernel panic' OR 'KASAN' OR 'use-after-free' AND 'io_uring' in system logs