CVE-2022-38181: Arm Bifrost GPU Use-After-Free Flaw

CVE-2022-38181 Overview

CVE-2022-38181 is a Use-After-Free vulnerability in the Arm Mali GPU kernel driver that allows unprivileged users to access freed memory due to mishandled GPU memory operations. This vulnerability affects multiple Mali GPU driver families including Bifrost, Valhall, and Midgard, impacting a wide range of Android devices and embedded systems that utilize Arm Mali GPUs.

Critical Impact

This vulnerability is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating active exploitation in the wild. Successful exploitation can lead to arbitrary code execution with elevated privileges on affected devices.

Affected Products

• Arm Bifrost GPU Kernel Driver r0p0 through r38p1, and r39p0
• Arm Valhall GPU Kernel Driver r19p0 through r38p1, and r39p0
• Arm Midgard GPU Kernel Driver r4p0 through r32p0

Discovery Timeline

• 2022-10-25 - CVE-2022-38181 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2022-38181

Vulnerability Analysis

This Use-After-Free (CWE-416) vulnerability exists within the Arm Mali GPU kernel driver's memory management subsystem. The flaw occurs when GPU memory operations are improperly handled, creating a race condition where memory can be accessed after it has been freed. This type of vulnerability is particularly dangerous in kernel drivers as it can be leveraged to achieve kernel-level code execution from an unprivileged user context.

The vulnerability has been documented in GitHub Security Advisory GHSL-2022-054 and was notably discussed in a GitHub Blog post demonstrating its use in compromising Google Pixel devices. The widespread deployment of Mali GPUs in Android smartphones and tablets makes this vulnerability particularly impactful across the mobile ecosystem.

Root Cause

The root cause of CVE-2022-38181 lies in improper synchronization and reference counting within the GPU memory management code. When GPU memory regions are allocated and subsequently freed, the driver fails to properly invalidate all references to the freed memory. This allows a malicious application to retain a dangling pointer to the freed memory region, which can then be reallocated for a different purpose, enabling the attacker to manipulate kernel memory structures.

Attack Vector

The attack vector involves a local unprivileged application making specific GPU memory allocation and deallocation requests in a controlled sequence. By carefully timing these operations, an attacker can create a scenario where:

1. Memory is allocated for GPU operations
2. The memory is freed but references remain valid
3. The freed memory is reallocated for kernel objects
4. The attacker uses the dangling reference to corrupt kernel data structures

This attack chain can ultimately lead to arbitrary code execution with kernel privileges, effectively giving the attacker complete control over the affected device. Technical details and proof-of-concept information are available in the Packet Storm Exploit Report.

Detection Methods for CVE-2022-38181

Indicators of Compromise

• Anomalous GPU memory allocation patterns from unprivileged applications
• Unexpected kernel crashes or system instability related to Mali GPU driver operations
• Evidence of privilege escalation attempts following GPU-intensive operations
• Suspicious processes making excessive ioctl calls to Mali GPU device nodes

Detection Strategies

• Monitor for unusual patterns of GPU memory allocation and deallocation from user-space applications
• Implement kernel-level monitoring for Use-After-Free access patterns in GPU driver memory regions
• Deploy endpoint detection solutions capable of identifying exploitation attempts targeting known Mali GPU vulnerabilities
• Audit device driver version information to identify systems running vulnerable Mali GPU kernel driver versions

Monitoring Recommendations

• Enable kernel auditing for GPU-related system calls and ioctl operations
• Implement runtime integrity monitoring for kernel memory structures
• Deploy SentinelOne Singularity platform for real-time behavioral detection of exploitation attempts
• Maintain asset inventory of devices with Mali GPU hardware to track patch compliance

How to Mitigate CVE-2022-38181

Immediate Actions Required

• Apply vendor-provided security patches for affected Arm Mali GPU kernel drivers immediately
• Prioritize patching for devices listed in CISA KEV catalog requirements
• Restrict installation of untrusted applications on affected devices
• Enable application sandboxing and security features where available
• Consider network isolation for unpatched devices until remediation is complete

Patch Information

Arm has released security updates addressing this vulnerability. Organizations should consult the ARM Mali GPU Driver Vulnerabilities page and ARM Security Updates portal for the latest patched driver versions. For Android devices, ensure the latest security patch level from the device manufacturer is installed, as this vulnerability has been addressed in Android security bulletins.

Workarounds

• Limit installation of applications to trusted sources only (enterprise app stores or Google Play)
• Implement Mobile Device Management (MDM) policies to control application installation on affected devices
• Enable SELinux in enforcing mode on Android devices to limit exploitation impact
• Consider application whitelisting to prevent unauthorized code execution on affected systems

# Check Mali GPU driver version on Android (requires ADB access)
adb shell cat /sys/module/mali_kbase/version
# Or for older drivers:
adb shell cat /sys/module/mali/version

# Verify Android security patch level
adb shell getprop ro.build.version.security_patch