CVE-2024-42266
📋 TL;DR
A race condition vulnerability in the Linux kernel's Btrfs filesystem can cause a kernel panic when handling write errors. This affects systems using Btrfs filesystem with specific error conditions during write operations. The vulnerability allows local attackers to crash the system, leading to denial of service.
💻 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 and denial of service, potentially causing data corruption or loss if the system is performing critical operations.
Likely Case
System crash or kernel panic when specific write error conditions occur, resulting in temporary denial of service until system reboot.
If Mitigated
No impact if the system is not using Btrfs filesystem or if the specific error conditions don't occur.
🎯 Exploit Status
Exploitation requires local access and ability to trigger specific Btrfs write error conditions. The vulnerability was discovered through fuzzing and specific test cases.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in kernel commits 061e41581606000a83ce0f0f01d6ad338f3704e9 and 478574370bef7951fbd9ef5155537d6cbed49472
Vendor Advisory: https://git.kernel.org/stable/c/061e41581606000a83ce0f0f01d6ad338f3704e9
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix. 2. Check with your distribution for backported patches. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Avoid Btrfs filesystem
linuxUse alternative filesystems like ext4 or XFS instead of Btrfs
Limit write operations
linuxImplement monitoring and limits on Btrfs write operations to reduce likelihood of triggering the error condition
🧯 If You Can't Patch
- Implement strict access controls to limit who can write to Btrfs filesystems
- Monitor system logs for Btrfs error messages and kernel panic indicators
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if Btrfs is in use: 'uname -r' and 'cat /proc/filesystems | grep btrfs'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check that Btrfs operations complete without kernel panics under stress testing📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages related to Btrfs
- BTRFS assertion failed errors
- folio_test_locked assertion failures
Network Indicators:
- None - this is a local filesystem vulnerability
SIEM Query:
Search for kernel logs containing 'BTRFS: error', 'assertion failed: folio_test_locked', or kernel panic messages