CVE-2026-25278 in Snapdragon Auto
Summary
by MITRE • 09/17/2026
Memory Corruption when processing I2C transfer requests due to a race condition between memory allocation and data copying.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability described constitutes a critical memory corruption flaw arising from a race condition within the handling of Inter-Integrated Circuit, or I2C, transfer requests in operating system kernels or embedded firmware environments. This specific defect occurs during the sequence where kernel space allocates temporary buffers for data transmission and subsequently copies user-provided payload data into those allocated regions. The core technical failure lies in the lack of proper synchronization mechanisms between these two distinct operations. When a process initiates an I2C transfer, it typically provides pointers to memory locations containing the data to be sent or received. The kernel driver must allocate internal buffers and copy this data before initiating the hardware transaction. If there is no strict locking mechanism ensuring that the user-space buffer remains immutable during the entire allocation and copying window, a malicious actor can exploit the timing gap by modifying the source memory contents via concurrent threads or processes after the pointer has been validated but before the actual memcpy operation completes. This race condition allows for arbitrary write primitives where an attacker can cause the kernel to copy unintended data into its own memory space, potentially overwriting critical control structures such as function pointers, return addresses, or security metadata like stack canaries and heap metadata headers.
From a technical perspective, this flaw aligns with CWE-362, which defines concurrent execution using shared resources without proper synchronization. The specific manifestation involves a Time-of-check to Time-of-use pattern where the initial validation of user input is decoupled from its actual usage due to asynchronous memory operations. In many Linux kernel implementations or similar RTOS environments, I2C subsystems often handle multiple simultaneous requests through workqueues or interrupt handlers. If the driver fails to pin the user pages in physical memory using functions like get_user_pages_fast or if it does not hold a mutex across the entire duration of data copying and buffer allocation, the operating system's virtual memory manager may allow page faults that trigger context switches. During these switches, another thread with sufficient privileges can alter the source buffer contents. This leads to heap corruption when the overwritten data resides in dynamically allocated kernel heaps or stack overflow scenarios if the copied data exceeds expected bounds due to manipulated length fields derived from the race condition window.
The operational impact of this vulnerability is severe and multifaceted, primarily centering on privilege escalation and system instability. An attacker who successfully exploits this race condition can achieve arbitrary code execution with kernel-level privileges, effectively compromising the entire host system. This level of access allows for complete data exfiltration, installation of persistent backdoors, or modification of security policies such as SELinux contexts or AppArmor profiles. Furthermore, even if exploitation fails to yield immediate code execution, the memory corruption can lead to denial-of-service conditions by crashing the kernel through panic-inducing overwrites of critical structures like task_structs or slab cache metadata. In embedded systems where I2C is commonly used for communicating with sensors and peripherals, such instability could result in physical safety hazards if those devices control industrial machinery, medical equipment, or automotive subsystems. The unpredictability inherent in race conditions makes reliable exploitation difficult but not impossible, particularly when combined with information leakage vulnerabilities that allow attackers to determine memory layout addresses required for successful payload delivery.
Mitigation strategies must address both the immediate code defect and broader architectural weaknesses. At the application driver level, developers should enforce strict serialization of I2C transfer requests by utilizing mutexes or spinlocks around the entire buffer allocation and data copying sequence. It is imperative that user-space memory pointers are pinned in physical RAM using appropriate kernel APIs to prevent page faults during the copy operation, thereby ensuring the source data remains constant throughout the transaction. Additionally, implementing bounds checking on all length fields provided by userspace before any allocation occurs can reduce the attack surface for buffer overflow variants of this race condition. On a systemic level, enabling Kernel Hardening features such as KASLR to randomize memory addresses and Stack Smashing Protection to detect overwrites early can mitigate exploitation success rates. Regular static analysis using tools that specialize in detecting concurrency bugs and dynamic fuzzing with coverage-guided engines like AFL++ or libFuzzer are essential for identifying these timing-dependent flaws before deployment. Compliance with secure coding standards such as CERT C Secure Coding Standard, specifically rules regarding concurrent access to shared resources, should be enforced during code review processes to prevent recurrence of CWE-362 related defects in low-level system drivers.