CVE-2025-23159 in Linux
Summary
by MITRE • 05/01/2025
In the Linux kernel, the following vulnerability has been resolved:
media: venus: hfi: add a check to handle OOB in sfr region
sfr->buf_size is in shared memory and can be modified by malicious user. OOB write is possible when the size is made higher than actual sfr data buffer. Cap the size to allocated size for such cases.
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Analysis
by VulDB Data Team • 03/15/2026
The vulnerability identified as CVE-2025-23159 resides within the Linux kernel's media subsystem, specifically in the venus hardware abstraction layer component responsible for handling video decoding operations. This flaw manifests in the handling of shared memory regions used for communication between user space and kernel space components. The venus driver implements a hardware interface that manages video processing operations through a specialized firmware interface, making it a critical component in mobile and embedded systems where hardware acceleration is utilized for multimedia processing.
The technical implementation flaw stems from inadequate bounds checking within the sfr (system firmware region) buffer management mechanism. The sfr->buf_size parameter represents a value that is stored in shared memory and can be manipulated by user-space processes with appropriate privileges. When a malicious actor deliberately sets this buffer size parameter to exceed the actual allocated buffer space, the system becomes vulnerable to out-of-bounds write conditions. This particular vulnerability falls under the CWE-129 category of Improper Validation of Array Index, specifically manifesting as an out-of-bounds write scenario where kernel memory can be overwritten beyond the intended buffer boundaries.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates potential attack vectors for privilege escalation and system stability compromise. An attacker with access to the venus device interface could exploit this condition to overwrite critical kernel memory structures, potentially leading to denial of service conditions or arbitrary code execution within kernel space. The vulnerability affects systems utilizing the venus hardware interface for video processing, which includes various mobile platforms and embedded devices that rely on Qualcomm's video processing hardware. The shared memory nature of the buffer size parameter makes this particularly dangerous as it allows user-space processes to directly influence kernel memory layout through crafted input parameters.
Mitigation strategies for this vulnerability should focus on implementing proper bounds checking mechanisms within the kernel driver code to validate buffer size parameters against allocated memory boundaries. The recommended fix involves adding explicit size validation checks that cap the sfr->buf_size value to the maximum allocated buffer size, preventing any potential out-of-bounds write conditions. System administrators should ensure that all kernel updates containing this fix are applied promptly, as the vulnerability requires no special privileges beyond access to the venus device interface. Additionally, monitoring systems should be configured to detect anomalous buffer size values in the venus driver interface, as this could indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation in kernel space components and aligns with ATT&CK technique T1068 for bypassing user execution restrictions, where an attacker could leverage kernel memory corruption to escalate privileges and gain unauthorized access to system resources.