CVE-2024-53095
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's CIFS/SMB client where network namespace references are incorrectly managed. It allows kernel memory corruption when CIFS mounts exist in non-root network namespaces that are destroyed while connections are active. Systems running Linux kernels with CIFS mounts in containerized or network namespace environments 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and potential privilege escalation via memory corruption.
Likely Case
System instability or crash when network namespaces with active CIFS mounts are destroyed, particularly in container orchestration environments.
If Mitigated
No impact if CIFS is not used or if mounts are only in root network namespace.
🎯 Exploit Status
Exploitation requires local access and specific workload conditions. The vulnerability was discovered through customer reports rather than active exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in kernel commits c7f9282fc27fc36dbaffc8527c723de264a132f8, e8c71494181153a134c96da28766a57bd1eac8cb, ef7134c7fc48e1441b398e55a862232868a6f0a7
Vendor Advisory: https://git.kernel.org/stable/c/c7f9282fc27fc36dbaffc8527c723de264a132f8
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Check your distribution's security advisories for backported patches. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Avoid CIFS mounts in non-root namespaces
linuxPrevent the vulnerable condition by not mounting CIFS shares in container or non-root network namespaces.
Use alternative network filesystems
linuxReplace CIFS mounts with NFS or other network filesystems that don't have this specific vulnerability.
🧯 If You Can't Patch
- Isolate systems with CIFS mounts to root network namespace only
- Implement strict pod/container lifecycle management to ensure clean unmount before namespace destruction
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if CIFS is used in non-root network namespaces. Run: uname -r and examine mount configurations.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the fix commits. Check with: grep -q 'c7f9282fc27fc36dbaffc8527c723de264a132f8\|e8c71494181153a134c96da28766a57bd1eac8cb\|ef7134c7fc48e1441b398e55a862232868a6f0a7' /proc/version_signature📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages mentioning fib_rules_lookup, CIFS reconnection errors, network namespace destruction with active mounts
Network Indicators:
- Unexpected CIFS reconnection attempts followed by system crashes
SIEM Query:
kernel.panic OR "CIFS: VFS:.*has not responded" OR "use-after-free" AND "network namespace"