CVE-2025-21849
📋 TL;DR
This CVE describes a race condition in the Linux kernel's i915 graphics driver where improper spin lock usage in interruptible contexts could lead to deadlocks. Systems using Intel integrated graphics with affected kernel versions are vulnerable. The vulnerability could cause system instability or denial of service.
💻 Affected Systems
- Linux kernel with Intel i915 graphics driver
📦 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 →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 deadlock requiring hard reboot, potentially causing data loss or service disruption
Likely Case
System instability, graphical artifacts, or application crashes when graphics-intensive operations trigger the race condition
If Mitigated
Minor performance impact from proper interrupt handling with no security compromise
🎯 Exploit Status
Requires precise timing to trigger race condition and local system access
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commit c088387ddd6482b40f21ccf23db1125e8fa4af7e or later
Vendor Advisory: https://git.kernel.org/stable/c/2bf1f4c129db7a10920655b000f0292f1ee509c2
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution's repositories
2. Reboot system to load new kernel
3. Verify kernel version after reboot
🔧 Temporary Workarounds
Disable Intel graphics acceleration
linuxTemporarily disable hardware acceleration to avoid triggering the vulnerable code path
echo 'options i915 modeset=0' > /etc/modprobe.d/i915.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local user access to systems with Intel graphics
- Monitor system logs for kernel panic or deadlock indicators
🔍 How to Verify
Check if Vulnerable:
Check if current kernel version is before the fix commit: uname -r and compare with distribution's patched kernel versionCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commit: grep -q 'c088387ddd6482b40f21ccf23db1125e8fa4af7e' /proc/version_signature || echo 'Check kernel changelog'📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- System hang/soft lockup warnings
- Graphics driver crash logs in dmesg
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("soft lockup" OR "hung task" OR "i915" AND "panic")