CVE-2023-53110
📋 TL;DR
A race condition vulnerability in the Linux kernel's SMC-R (Shared Memory Communications over RDMA) implementation allows a NULL pointer dereference when terminating network connections under stress conditions. This affects Linux systems using SMC-R networking, potentially causing kernel panics and denial of service. The vulnerability requires local access or ability to trigger specific network operations.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash and complete denial of service, requiring physical or remote console access to reboot.
Likely Case
System instability or crash during high network load when SMC-R connections are terminated, causing temporary service disruption.
If Mitigated
Minor performance impact during connection termination with proper kernel patches applied.
🎯 Exploit Status
Exploitation requires specific timing conditions during SMC-R connection termination under stress, making reliable exploitation difficult.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing commits: 22a825c541d775c1dbe7b2402786025acad6727b, 31817c530768b0199771ec6019571b4f0ddbf230, 3c270435db8aa34929263dddae8fd050f5216ecb, 3ebac7cf0a184a8102821a7a00203f02bebda83c, b108bd9e6be000492ebebe867daa699285978a10
Vendor Advisory: https://git.kernel.org/stable/c/22a825c541d775c1dbe7b2402786025acad6727b
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable SMC-R networking
linuxDisable SMC-R module if not required for system functionality
modprobe -r smc
echo 'blacklist smc' >> /etc/modprobe.d/blacklist.conf
🧯 If You Can't Patch
- Disable SMC-R module if not required for operations
- Monitor system logs for kernel panic events and implement high availability/failover
🔍 How to Verify
Check if Vulnerable:
Check if SMC module is loaded: lsmod | grep smc AND check kernel version against patched versionsCheck Version:
uname -rVerify Fix Applied:
Verify kernel version contains fix commits and SMC module functions normally under stress testing📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages in /var/log/messages or dmesg
- NULL pointer dereference errors mentioning smc_cdc_tx_handler
Network Indicators:
- Unusual SMC-R connection termination patterns
SIEM Query:
source="kernel" AND ("panic" OR "NULL pointer" OR "smc_cdc_tx_handler")🔗 References
- https://git.kernel.org/stable/c/22a825c541d775c1dbe7b2402786025acad6727b
- https://git.kernel.org/stable/c/31817c530768b0199771ec6019571b4f0ddbf230
- https://git.kernel.org/stable/c/3c270435db8aa34929263dddae8fd050f5216ecb
- https://git.kernel.org/stable/c/3ebac7cf0a184a8102821a7a00203f02bebda83c
- https://git.kernel.org/stable/c/b108bd9e6be000492ebebe867daa699285978a10
