Description

An issue was discovered in DPU Samsung Mobile Processor Exynos 1280, 2200, 1380, 1480, 2400, 1580, 2500, 1680, and 2600. A TOCTOU race condition in the Exynos DRM HDR Driver leads to a heap overflow, causing a kernel crash.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "2.8",
  "pubDate": "2026-09-14T01:16:27.473Z",
  "pubdate": "2026-09-14T01:16:27.473Z",
  "executiveSummary": "A Time-of-Check to Time-of-Use (TOCTOU) race condition exists within the Exynos DRM HDR driver, affecting various Samsung Mobile Processor models including Exynos 1280, 2200, 1380, 1480, 2400, 1580, 2500, 1680, and 2600.\nThis vulnerability originates from an asynchronous race condition during memory management operations within the kernel-mode display driver, potentially leading to a heap-based buffer overflow.\nSuccessful exploitation results in kernel memory corruption, which invariably triggers a kernel panic, leading to a denial-of-service (DoS) condition on the affected mobile device.\nThe vulnerability requires an attacker to possess the capability to execute code in an environment with sufficient privileges to interact with the DRM driver's character device or ioctl interface.\nThe impact is significant due to the critical nature of the DRM subsystem, which operates with elevated kernel privileges, necessitating immediate attention to process synchronization and object lifetime management within the driver.",
  "technicalDetails": "The vulnerability manifests as a TOCTOU race condition within the Exynos DRM HDR driver component of the kernel. This type of concurrency flaw occurs when a program checks the state of a resource (in this case, memory allocated for HDR metadata or buffer descriptors) and then acts upon that resource, but the resource's state is modified by a concurrent thread between the check and the act.\nSpecifically, the DRM driver likely performs validation on buffer parameters or size constraints before performing a copy operation into a kernel heap-allocated buffer. Because the validation check and the subsequent memory copy are not atomic, an attacker-controlled thread can modify the shared parameters after the initial verification but before the completion of the copy routine.\nThis race window allows the driver to trust an outdated or invalidated size parameter during the copy operation, leading to a heap-based buffer overflow. During the copy process, the driver writes data beyond the boundary of the allocated kernel heap chunk, corrupting adjacent heap metadata or unrelated object data.\nThe attack flow typically involves an adversary opening the relevant DRM device file and invoking ioctl requests that manipulate HDR frame metadata. By rapidly spawning concurrent threads to repeatedly update these ioctl parameters while the kernel is processing the memory copy, the attacker creates a predictable race window. The resulting heap corruption overwrites critical kernel structures, leading to an immediate kernel crash, typically resulting in a bugcheck or illegal memory access exception.\nSince the vulnerability resides within the kernel-space DRM driver, it bypasses standard user-space memory protection mechanisms. While the primary documented impact is a kernel crash, such heap corruption primitives, if precisely controlled, could theoretically be utilized for further privilege escalation or arbitrary code execution within the kernel context, depending on the layout of the kernel heap at the time of the exploit.\nThe affected versions include Exynos 1280, 2200, 1380, 1480, 2400, 1580, 2500, 1680, and 2600. The exploitation requires the attacker to have enough privileges to interact with the DRM driver, effectively requiring an initial foothold on the device to issue ioctl commands to the hardware-specific driver interface."
}