CVE-2024-46691
📋 TL;DR
This CVE addresses a NULL pointer dereference vulnerability in the Linux kernel's USB Type-C UCSI driver. The issue occurs when unregistering UCSI during system shutdown or driver removal, potentially causing a kernel panic or system crash. It affects Linux systems using Qualcomm PMIC GLINK communication with USB Type-C controllers.
💻 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 denial of service, potentially requiring physical reboot.
Likely Case
System instability during shutdown or driver removal, with kernel log errors but no persistent damage.
If Mitigated
Minor kernel log errors during shutdown with no functional impact when proper scheduling is implemented.
🎯 Exploit Status
Requires triggering UCSI unregistration during specific timing windows, typically during system shutdown or driver removal.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel commits 095b0001aefddcd9361097c971b7debc84e72714 and 11bb2ffb679399f99041540cf662409905179e3a
Vendor Advisory: https://git.kernel.org/stable/c/095b0001aefddcd9361097c971b7debc84e72714
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing fixes 095b0001aefddcd9361097c971b7debc84e72714 and 11bb2ffb679399f99041540cf662409905179e3a. 2. Reboot system to load new kernel.
🔧 Temporary Workarounds
Disable UCSI functionality
linuxRemove or disable USB Type-C UCSI driver if not required
modprobe -r ucsi_glink
echo 'blacklist ucsi_glink' > /etc/modprobe.d/disable-ucsi.conf
🧯 If You Can't Patch
- Avoid system shutdowns or driver removal operations on affected systems
- Monitor kernel logs for UCSI errors and restart affected services if errors appear
🔍 How to Verify
Check if Vulnerable:
Check kernel version and if UCSI GLINK driver is loaded: 'uname -r' and 'lsmod | grep ucsi_glink'Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fixes and check kernel logs for absence of 'failed to send UCSI write request: -5' errors📡 Detection & Monitoring
Log Indicators:
- Kernel log entries containing: 'failed to send UCSI write request: -5'
- System crash logs during shutdown
Network Indicators:
- None - local kernel vulnerability
SIEM Query:
source="kernel" AND "failed to send UCSI write request: -5"