CVE-2024-41083
📋 TL;DR
This Linux kernel vulnerability allows a NULL pointer dereference in the netfs subsystem when handling mmap'd writes during DIO (Direct I/O) operations. It can cause kernel crashes (oops/panics) leading to denial of service. Systems running affected Linux kernel versions with netfs functionality are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and denial of service, potentially causing data loss or service disruption.
Likely Case
System crash or instability when specific DIO and mmap write operations occur simultaneously.
If Mitigated
Minor performance impact from the additional mapping check, with no security impact when patched.
🎯 Exploit Status
Exploitation requires local access and ability to trigger the specific race condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees via git commits: 3473eb87afd402e415a8ca885b284ea0420dde25 and a81c98bfa40c11f8ea79b5a9b3f5fda73bfbb4d2
Vendor Advisory: https://git.kernel.org/stable/c/3473eb87afd402e415a8ca885b284ea0420dde25
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution. 2. Download and apply kernel patches from stable tree. 3. Recompile kernel if building from source. 4. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable netfs functionality
linuxRemove or disable netfs module if not required (not recommended for systems needing this functionality).
modprobe -r netfs
🧯 If You Can't Patch
- Restrict local user access to minimize attack surface
- Monitor system logs for kernel oops/panic events related to netfs
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if netfs is loaded: 'uname -r' and 'lsmod | grep netfs'Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated and check dmesg for absence of netfs-related NULL pointer errors📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages mentioning netfs_page_mkwrite
- NULL pointer dereference errors in dmesg
- Page fault errors with netfs trace events
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("netfs_page_mkwrite" OR "NULL pointer dereference" AND "netfs")