CVE-2023-53382
📋 TL;DR
A NULL pointer dereference vulnerability in the Linux kernel's SMC (Shared Memory Communications) subsystem allows local attackers to cause a kernel panic and system crash. This affects systems using SMC-R (RDMA) with Mellanox ConnectX-4 adapters when SMCRv2 fails and falls back to SMCRv1. The vulnerability requires local access to trigger the crash.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Local denial of service causing kernel panic and system crash, potentially leading to data loss or service disruption.
Likely Case
Local denial of service causing system instability or crash when specific SMC-R configurations fail.
If Mitigated
No impact if SMC-R is not used or if systems are patched.
🎯 Exploit Status
Requires local access and specific SMC-R configuration to trigger. Not remotely exploitable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 35112271672ae98f45df7875244a4e33aa215e31, 9540765d1882d15497d880096de99fafabcfa08c, or d33be18917ffe69865dfed18b0a67b0dee0b47d7
Vendor Advisory: https://git.kernel.org/stable/c/35112271672ae98f45df7875244a4e33aa215e31
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For distributions: Use package manager (apt/yum/dnf) to install latest kernel updates. 3. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable SMC-R
LinuxDisable SMC-R (Shared Memory Communications over RDMA) if not required.
echo 'blacklist smc' > /etc/modprobe.d/disable-smc.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local access to systems using SMC-R configurations
- Monitor for kernel panic/crash events related to SMC-R
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if SMC module is loaded: uname -r && lsmod | grep smcCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commits: check distribution security advisories or kernel changelog📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs mentioning 'smc' or 'NULL pointer dereference'
- System crash/reboot events
Network Indicators:
- SMC-R connection failures followed by system instability
SIEM Query:
source="kernel" AND ("NULL pointer dereference" OR "smc" OR "kernel panic")