CVE-2024-35999
📋 TL;DR
A race condition vulnerability exists in the Linux kernel's SMB3 client implementation where a missing lock when accessing session channel indices could lead to data corruption or crashes. This affects systems using the SMB3 protocol for file sharing. The vulnerability requires local access to exploit.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic or system crash leading to denial of service, or potential data corruption in SMB sessions.
Likely Case
System instability or crashes when multiple processes access SMB shares concurrently, causing temporary service disruption.
If Mitigated
Minor performance impact or isolated process crashes if proper isolation exists.
🎯 Exploit Status
Requires local access and concurrent SMB operations to trigger race condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees (commits: 0fcf7e219448e937681216353c9a58abae6d3c2e, 60ab245292280905603bc0d3654f4cf8fceccb00, etc.)
Vendor Advisory: https://git.kernel.org/stable/c/0fcf7e219448e937681216353c9a58abae6d3c2e
Restart Required: Yes
Instructions:
1. Update to latest stable kernel version containing the fix. 2. For distributions: Use package manager (apt/yum/dnf) to update kernel. 3. Reboot system after update.
🔧 Temporary Workarounds
Disable SMB3 client
linuxPrevent use of SMB3 protocol if not required
# Consider removing or disabling SMB client modules if not needed
# Check with: lsmod | grep cifs
# Remove: rmmod cifs
🧯 If You Can't Patch
- Restrict local user access to systems using SMB shares
- Implement process isolation and resource limits to contain potential crashes
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if SMB3 is in use. Vulnerable if using affected kernel with SMB3 client active.Check Version:
uname -rVerify Fix Applied:
Verify kernel version is updated to include the fix commits, and check that SMB3 operations work without crashes.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- SMB client crash logs
- System instability during file operations
Network Indicators:
- Unusual SMB disconnections
- Failed SMB operations
SIEM Query:
source="kernel" AND ("panic" OR "oops") AND ("smb" OR "cifs")🔗 References
- https://git.kernel.org/stable/c/0fcf7e219448e937681216353c9a58abae6d3c2e
- https://git.kernel.org/stable/c/60ab245292280905603bc0d3654f4cf8fceccb00
- https://git.kernel.org/stable/c/8094a600245e9b28eb36a13036f202ad67c1f887
- https://git.kernel.org/stable/c/98c7ed29cd754ae7475dc7cb3f33399fda902729
- https://git.kernel.org/stable/c/0fcf7e219448e937681216353c9a58abae6d3c2e
- https://git.kernel.org/stable/c/60ab245292280905603bc0d3654f4cf8fceccb00
- https://git.kernel.org/stable/c/8094a600245e9b28eb36a13036f202ad67c1f887
- https://git.kernel.org/stable/c/98c7ed29cd754ae7475dc7cb3f33399fda902729
