CVE-2022-50239
📋 TL;DR
A memory corruption vulnerability in the Linux kernel's Qualcomm CPU frequency driver allows writing to read-only memory regions. This can cause kernel oops (crashes) or potentially be exploited for privilege escalation. Affects Linux systems with Qualcomm-based hardware using the vulnerable cpufreq driver.
💻 Affected Systems
- Linux kernel with Qualcomm CPU frequency driver (qcom-cpufreq)
📦 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 →⚠️ Risk & Real-World Impact
Worst Case
Kernel panic leading to system crash, or potential privilege escalation if combined with other vulnerabilities to achieve arbitrary code execution in kernel context.
Likely Case
System instability, kernel oops, or crashes during CPU frequency scaling operations, particularly during boot or power state transitions.
If Mitigated
Limited to denial of service on affected systems; proper kernel hardening and exploit mitigations reduce privilege escalation risk.
🎯 Exploit Status
Requires local access to trigger the vulnerable code path. The vulnerability is triggered during CPU frequency driver initialization, which typically happens at boot or module load.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Linux kernel with commit 01039fb8e90c9cb684430414bff70cea9eb168c5 or later
Vendor Advisory: https://git.kernel.org/stable/c/01039fb8e90c9cb684430414bff70cea9eb168c5
Restart Required: Yes
Instructions:
1. Update Linux kernel to version containing the fix commit. 2. For distributions: Use package manager (apt/yum/dnf) to install latest kernel updates. 3. Reboot system to load patched kernel.
🔧 Temporary Workarounds
Disable qcom-cpufreq module
linuxPrevent loading of the vulnerable driver module
echo 'blacklist qcom_cpufreq' >> /etc/modprobe.d/blacklist-qcom-cpufreq.conf
update-initramfs -u
reboot
🧯 If You Can't Patch
- Restrict local user access to prevent untrusted users from triggering the vulnerability
- Implement kernel hardening features (KASLR, stack protection) to reduce exploit impact
🔍 How to Verify
Check if Vulnerable:
Check if qcom_cpufreq module is loaded: lsmod | grep qcom_cpufreq. Check kernel version against patched versions.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commit: grep -q '01039fb8e90c9cb684430414bff70cea9eb168c5' /proc/version_signature || echo 'Check kernel changelog'📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages mentioning 'Unable to handle kernel write to read-only memory'
- Call trace including qcom_cpufreq_msm8939_name_version or qcom_cpufreq_probe
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("read-only memory" OR "qcom_cpufreq" OR "Oops: 9600004f")