CVE-2022-48637
📋 TL;DR
This CVE describes a use-after-free vulnerability in the Linux kernel's bnxt network driver. When handling PTP timestamping, the driver incorrectly retains access to a network packet buffer after transferring ownership to a worker thread, potentially allowing local attackers to execute arbitrary code or crash the system. Systems using affected Linux kernel versions with Broadcom NetXtreme-E network adapters are vulnerable.
💻 Affected Systems
- Linux kernel with bnxt driver
📦 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
Local privilege escalation to kernel-level code execution, potentially leading to full system compromise, data theft, or persistent backdoor installation.
Likely Case
Kernel panic or system crash causing denial of service, potentially leading to data loss or service disruption.
If Mitigated
Minimal impact if proper kernel hardening, privilege separation, and exploit mitigations are in place.
🎯 Exploit Status
Requires local access and knowledge of kernel exploitation techniques. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in Linux kernel stable releases containing commits: 08483e4c0c83b221b8891434a04cec405dee94a6, 32afa1f23e42cc635ccf4c39f24514d03d1e8338, c31f26c8f69f776759cbbdfb38e40ea91aa0dd65
Vendor Advisory: https://git.kernel.org/stable/c/08483e4c0c83b221b8891434a04cec405dee94a6
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.
🔧 Temporary Workarounds
Disable PTP timestamping
linuxDisable Precision Time Protocol timestamping on Broadcom NetXtreme-E network adapters
ethtool -T <interface> | grep 'PTP Hardware Clock:'
# If enabled, consult documentation for disabling PTP on your specific adapter
Use alternative network adapter
linuxReplace or avoid using Broadcom NetXtreme-E adapters in critical systems
🧯 If You Can't Patch
- Implement strict access controls to limit local user access to vulnerable systems
- Enable kernel hardening features like KASLR, SMEP, SMAP, and stack canaries to reduce exploit success
🔍 How to Verify
Check if Vulnerable:
Check if system uses bnxt driver and has PTP enabled: 'lsmod | grep bnxt' and 'ethtool -T <interface>'Check Version:
uname -rVerify Fix Applied:
Check kernel version contains fix commits: 'uname -r' and verify against patched kernel versions from distribution vendor📡 Detection & Monitoring
Log Indicators:
- Kernel panic logs
- OOM killer activity related to network operations
- Unexpected system crashes
Network Indicators:
- Unusual local network traffic patterns from single host
SIEM Query:
source="kernel" AND ("panic" OR "Oops" OR "general protection fault") AND process="bnxt"🔗 References
- https://git.kernel.org/stable/c/08483e4c0c83b221b8891434a04cec405dee94a6
- https://git.kernel.org/stable/c/32afa1f23e42cc635ccf4c39f24514d03d1e8338
- https://git.kernel.org/stable/c/c31f26c8f69f776759cbbdfb38e40ea91aa0dd65
- https://git.kernel.org/stable/c/08483e4c0c83b221b8891434a04cec405dee94a6
- https://git.kernel.org/stable/c/32afa1f23e42cc635ccf4c39f24514d03d1e8338
- https://git.kernel.org/stable/c/c31f26c8f69f776759cbbdfb38e40ea91aa0dd65
