CVE-2026-22995
📋 TL;DR
A race condition in the Linux kernel's ublk driver allows use-after-free when partition scanning occurs during device teardown. This vulnerability could lead to kernel crashes or potential privilege escalation. It affects systems using the ublk driver for userspace block devices.
💻 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 leading to system crash or potential privilege escalation to kernel mode execution.
Likely Case
System instability, kernel crashes, or denial of service on affected systems.
If Mitigated
Minimal impact if systems aren't using ublk driver or have proper isolation.
🎯 Exploit Status
Requires local access and ability to trigger race condition between partition scan and device teardown.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits 72e28774e9644c2bdbb4920842fbf77103a15a85 and f0d385f6689f37a2828c686fb279121df006b4cb
Vendor Advisory: https://git.kernel.org/stable/c/72e28774e9644c2bdbb4920842fbf77103a15a85
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Reboot system to load new kernel. 3. Verify ublk driver is not causing crashes.
🔧 Temporary Workarounds
Disable ublk driver
linuxPrevent loading of the vulnerable ublk driver module
echo 'blacklist ublk' >> /etc/modprobe.d/blacklist-ublk.conf
rmmod ublk
Prevent ublk module autoload
linuxStop automatic loading of ublk driver
echo 'install ublk /bin/false' >> /etc/modprobe.d/disable-ublk.conf
🧯 If You Can't Patch
- Disable ublk driver if not required for system functionality
- Implement strict access controls to prevent unauthorized users from accessing ublk devices
🔍 How to Verify
Check if Vulnerable:
Check if ublk module is loaded: lsmod | grep ublkCheck Version:
uname -rVerify Fix Applied:
Check kernel version contains fix commits: uname -r and verify against patched kernel versions📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- Use-after-free warnings in dmesg
- System crashes related to ublk
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("ublk" OR "use-after-free" OR "kernel panic")