CVE-2024-47741
📋 TL;DR
A race condition in the Linux kernel's Btrfs filesystem allows concurrent lseek operations on the same file descriptor to cause a memory leak and potential use-after-free issues. This affects Linux systems using Btrfs with multi-threaded applications performing lseek operations. The vulnerability requires local access and multi-threaded programming patterns.
💻 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
Memory exhaustion leading to system instability, or use-after-free potentially causing kernel crashes or privilege escalation.
Likely Case
Memory leak causing gradual performance degradation over time in multi-threaded applications using lseek with SEEK_DATA/SEEK_HOLE.
If Mitigated
Minimal impact if systems don't use Btrfs or applications don't perform concurrent lseek operations on the same file descriptor.
🎯 Exploit Status
Exploitation requires local access and multi-threaded applications performing concurrent lseek operations. No public exploits known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 33d1310d4496e904123dab9c28b2d8d2c1800f97, 7ee85f5515e86a4e2a2f51969795920733912bad, a412ca489ac27b9d0e603499315b7139c948130d, f56a6d9c267ec7fa558ede7755551c047b1034cd
Vendor Advisory: https://git.kernel.org/stable/c/33d1310d4496e904123dab9c28b2d8d2c1800f97
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Avoid concurrent lseek operations
linuxModify applications to avoid concurrent lseek operations on the same file descriptor across multiple threads.
Use alternative filesystem
linuxUse ext4, xfs, or other filesystems instead of Btrfs for affected applications.
🧯 If You Can't Patch
- Monitor system memory usage for unusual leaks in multi-threaded applications
- Implement application-level locking around lseek operations on shared file descriptors
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if it contains the vulnerable Btrfs code. Use: uname -r and compare with distribution's security advisories.Check Version:
uname -rVerify Fix Applied:
After patching, verify kernel version contains the fix commits. Check distribution's changelog for the specific kernel version.📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages related to Btrfs or memory corruption
- System logs showing memory exhaustion
SIEM Query:
Search for kernel panic logs or memory allocation failures in system logs