CVE-2024-38631
📋 TL;DR
This CVE-2024-38631 is an out-of-bounds array access vulnerability in the Linux kernel's PAC1934 ADC driver. It allows attackers to read kernel memory beyond allocated buffers when accessing sysfs entries for average current/voltage measurements. Systems running affected Linux kernel versions with the PAC1934 driver loaded are vulnerable.
💻 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory disclosure leading to information leakage, potential privilege escalation if combined with other vulnerabilities, or system crash/instability.
Likely Case
Information disclosure of kernel memory contents, which could reveal sensitive data or aid in further exploitation.
If Mitigated
Limited impact if proper access controls restrict sysfs access to privileged users only.
🎯 Exploit Status
Requires local access and ability to read sysfs entries. Exploitation depends on specific memory layout.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees via provided git commits
Vendor Advisory: https://git.kernel.org/stable/c/51fafb3cd7fcf4f4682693b4d2883e2a5bfffe33
Restart Required: Yes
Instructions:
1. Update to patched kernel version from your distribution. 2. Reboot system. 3. Verify kernel version and that PAC1934 driver loads correctly.
🔧 Temporary Workarounds
Disable PAC1934 driver
linuxPrevent loading of vulnerable driver module
echo 'blacklist pac1934' >> /etc/modprobe.d/blacklist.conf
rmmod pac1934
Restrict sysfs access
linuxLimit access to vulnerable sysfs entries
chmod 600 /sys/bus/iio/devices/*/in_voltage*_average
chmod 600 /sys/bus/iio/devices/*/in_current*_average
🧯 If You Can't Patch
- Restrict local user access to system, especially untrusted users
- Monitor for unusual sysfs access patterns or kernel crash logs
🔍 How to Verify
Check if Vulnerable:
Check if PAC1934 driver is loaded: lsmod | grep pac1934 AND check kernel version against patched releasesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version is updated beyond patch commit dates and PAC1934 driver functions normally📡 Detection & Monitoring
Log Indicators:
- Kernel oops or panic logs
- Unusual sysfs access patterns in audit logs
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for: kernel:.*Oops OR kernel:.*panic AND pac1934 OR iio