CVE-2024-50273
📋 TL;DR
A use-after-free vulnerability in the Linux kernel's Btrfs filesystem occurs when deleting delayed references without properly reinitializing the list. This can cause kernel crashes or potential privilege escalation when specific conditions are met. Systems running vulnerable Linux kernel versions with Btrfs filesystem are affected.
💻 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 →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 →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
Kernel panic leading to system crash and denial of service, with potential for local privilege escalation if an attacker can trigger the condition repeatedly.
Likely Case
System crash or kernel panic when Btrfs operations trigger the specific delayed reference handling scenario, resulting in denial of service.
If Mitigated
No impact if the vulnerable code path is not triggered during normal Btrfs operations.
🎯 Exploit Status
Exploitation requires local access and specific Btrfs operations to trigger the vulnerable code path. Likely requires filesystem manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commit 2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6 or later
Vendor Advisory: https://git.kernel.org/stable/c/2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable Btrfs filesystem
linuxAvoid using Btrfs filesystem to prevent triggering the vulnerability
# Not recommended for production - consider alternative filesystems
Use alternative filesystem
linuxUse ext4, xfs, or other filesystems instead of Btrfs
# Format partitions with alternative filesystem: mkfs.ext4 /dev/sdX
🧯 If You Can't Patch
- Restrict local user access to systems with Btrfs filesystems
- Monitor for Btrfs-related kernel panics and implement rapid response procedures
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if Btrfs module is loaded: lsmod | grep btrfs && uname -rCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and contains the fix commit: uname -r && check distribution patch notes📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/kern.log or dmesg
- Btrfs-related crash reports
- System crash/reboot events
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "BUG") AND "btrfs"🔗 References
- https://git.kernel.org/stable/c/2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6
- https://git.kernel.org/stable/c/2fd0948a483e9cb2d669c7199bc620a21c97673d
- https://git.kernel.org/stable/c/50a3933760b427759afdd23156a7280a19357a92
- https://git.kernel.org/stable/c/93c5b8decc0ef39ba84f4211d2db6da0a4aefbeb
- https://git.kernel.org/stable/c/bf0b0c6d159767c0d1c21f793950d78486690ee0
- https://git.kernel.org/stable/c/c24fa427fc0ae827b2a3a07f13738cbf82c3f851
- https://git.kernel.org/stable/c/c9a75ec45f1111ef530ab186c2a7684d0a0c9245
- https://git.kernel.org/stable/c/f04be6d68f715c1473a8422fc0460f57b5e99931
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
