CVE-2016-2064 in Linux
Summary
by MITRE
sound/soc/msm/qdsp6v2/msm-audio-effects-q6-v2.c in the MSM QDSP6 audio driver for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allows attackers to cause a denial of service (buffer over-read) or possibly have unspecified other impact via a crafted application that makes an ioctl call specifying many commands.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability identified as CVE-2016-2064 resides within the MSM QDSP6 audio driver component of the Linux kernel version 3.x series, specifically in the msm-audio-effects-q6-v2.c file. This driver serves as a critical interface for audio processing on Qualcomm MSM (Multi-System Module) devices, which are widely deployed in Android smartphones and tablets through contributions from Qualcomm Innovation Center. The flaw manifests in the driver's handling of ioctl (input/output control) system calls, which are essential mechanisms for device communication and configuration within the kernel space. The vulnerability specifically affects how the driver processes multiple commands within a single ioctl call, creating a scenario where an attacker can manipulate the audio subsystem through carefully crafted applications.
The technical implementation of this vulnerability stems from inadequate bounds checking within the audio effects processing code. When a malicious application submits an ioctl command containing numerous audio processing commands, the driver fails to properly validate the number of commands or their memory boundaries. This oversight results in a buffer over-read condition where the driver attempts to access memory locations beyond the allocated buffer space. The CWE-129 weakness classification applies here, as the vulnerability represents an insufficient input validation issue that allows for improper handling of input data lengths. The buffer over-read can potentially lead to system instability, causing the audio subsystem to crash or the entire device to become unresponsive. In some cases, the memory corruption may be severe enough to allow for privilege escalation or arbitrary code execution, though the primary impact documented is denial of service.
The operational impact of this vulnerability extends beyond simple system crashes, as it represents a significant security risk for mobile device users and manufacturers. Mobile devices running affected kernel versions become susceptible to malicious applications that can exploit this weakness to disrupt audio functionality, potentially rendering the device unusable for communication purposes. The vulnerability affects a wide range of Qualcomm MSM-based devices, making it particularly concerning from a mass impact perspective. From an attacker's standpoint, this represents a low-effort method for achieving persistent denial of service, as the exploit requires only the ability to run a crafted application with audio permissions. The ATT&CK framework's T1059.003 technique for command and scripting interpreter applies here, as the vulnerability enables execution of malicious code through legitimate system interfaces. Additionally, the T1499.004 technique for network denial of service is relevant since the audio subsystem disruption can affect overall device usability and communication capabilities.
Mitigation strategies for CVE-2016-2064 should focus on both immediate patching and defensive measures. The primary solution involves applying kernel updates that include proper bounds checking and input validation for ioctl command processing in the msm-audio-effects-q6-v2.c driver. System administrators and device manufacturers should prioritize deployment of security patches that address the specific buffer over-read condition in the audio driver. Additionally, implementing runtime protections such as kernel address space layout randomization and stack canaries can help prevent exploitation attempts. Mobile device vendors should consider implementing application sandboxing mechanisms that limit audio-related system calls to prevent unauthorized access to kernel drivers. Network-level monitoring should also be employed to detect unusual patterns in audio subsystem usage that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation in kernel space drivers and serves as a reminder of the critical security implications that can arise from insufficient bounds checking in system-level components. Organizations should conduct regular security assessments of their kernel configurations and maintain updated threat intelligence to identify potential exploitation attempts against similar vulnerabilities in audio and multimedia subsystems.