CVE-2025-40325
📋 TL;DR
A race condition vulnerability in the Linux kernel's RAID10 discard handling could cause system instability or crashes when discard requests with REQ_NOWAIT flag are processed without proper barrier synchronization. This affects systems using Linux kernel with RAID10 arrays and discard operations. The vulnerability primarily impacts system administrators and users running RAID10 configurations.
💻 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
System crash or kernel panic leading to denial of service and potential data corruption in RAID10 arrays.
Likely Case
System instability, occasional crashes, or performance degradation during discard operations on RAID10 arrays.
If Mitigated
Minor performance impact during discard operations with proper synchronization.
🎯 Exploit Status
Exploitation requires local access and ability to trigger discard operations with REQ_NOWAIT flag on RAID10 arrays.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees (commits: 31d3156efe909b53ba174861a3da880c688f5edc, 31ff67982c5fa39c0093b9d9f429fef91c2494b7, 3db4404435397a345431b45f57876a3df133f3b4)
Vendor Advisory: https://git.kernel.org/stable/c/31d3156efe909b53ba174861a3da880c688f5edc
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check with your distribution for specific kernel updates. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Disable discard operations on RAID10 arrays
linuxPrevent discard operations on RAID10 arrays to avoid triggering the vulnerability
echo 0 > /sys/block/mdX/md/discard_zeroes_data
echo 0 > /sys/block/mdX/md/discard_max_bytes
🧯 If You Can't Patch
- Avoid using discard operations on RAID10 arrays
- Monitor system logs for warning messages related to RAID10 discard operations
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if RAID10 arrays are configured with discard enabled: cat /proc/mdstat && lsblk -DCheck Version:
uname -rVerify Fix Applied:
Verify kernel version contains the fix commits or check dmesg for absence of RAID10 discard warnings📡 Detection & Monitoring
Log Indicators:
- Kernel warning messages about RAID10 discard operations in dmesg or /var/log/kern.log
Network Indicators:
- None - this is a local storage subsystem issue
SIEM Query:
source="kernel" AND ("raid10" AND "discard")