Description

An issue was discovered in Samsung Mobile Processor Exynos 1280, 2200, 1380, 1480, 2400, 1580, 2500, 1680, and 2600. A Use-After-Free in the Exynos DRM HDR driver (due to improper cleanup upon vmap failure) leads to a kernel crash.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.2",
  "pubDate": "2026-09-14T01:16:27.677Z",
  "pubdate": "2026-09-14T01:16:27.677Z",
  "executiveSummary": "This vulnerability is a Use-After-Free (UAF) condition residing within the Exynos DRM HDR driver across multiple Samsung Mobile Processor models. The flaw stems from improper memory management and resource cleanup following a failure during the vmap operation.\nThe vulnerability affects Exynos 1280, 2200, 1380, 1480, 2400, 1580, 2500, 1680, and 2600 processors. A successful exploitation results in a kernel crash, causing a Denial of Service (DoS) for the affected mobile device.\nThe risk implication is significant as it pertains to the kernel memory management layer, potentially destabilizing the system. Exploitation requires the attacker to trigger a specific code path where a vmap request fails, allowing for a race condition or a dangling pointer dereference. While the primary identified impact is a kernel panic, UAF vulnerabilities often serve as primitives for more advanced exploitation techniques, such as privilege escalation or arbitrary code execution within the kernel context, depending on the heap layout and the timing of subsequent memory allocations.\nAs this involves the DRM (Direct Rendering Manager) driver, the attack surface is exposed to processes with the necessary permissions to interact with device drivers or GPU interfaces.",
  "technicalDetails": "The vulnerability is located within the Exynos DRM (Direct Rendering Manager) HDR driver, specifically in the error handling logic associated with memory mapping operations. The root cause is an improper resource cleanup sequence triggered when a vmap (virtual memory mapping) operation fails. In the event of a vmap failure, the driver erroneously proceeds to free or release internal memory structures that are still referenced or expected to be managed by other kernel threads or subsequent driver calls.\nThe technical flow of the vulnerability begins when a user-space application or a malicious process initiates an HDR display command that forces the driver to attempt a vmap operation on a buffer. When the kernel is under memory pressure or specific constraints are met, the vmap call returns an error indicating that the requested mapping cannot be completed. The driver's internal error handling routine fails to correctly nullify or re-initialize the pointers to the allocated memory before releasing the associated resources.\nBecause the reference to the memory remains in the driver's object state despite the resources being freed, a 'dangling pointer' scenario is created. When the driver or other kernel subsystems attempt to access or release this memory later—expecting it to be valid—the kernel dereferences the pointer to memory that has either been reclaimed by the kernel slab allocator for other uses or completely unmapped. This leads to a kernel-mode memory access violation, typically resulting in a kernel panic and a system crash (Denial of Service).\nExploitation requires the ability to influence or monitor the memory mapping state within the DRM subsystem. An attacker would likely attempt to synchronize an operation that triggers the vmap failure with a concurrent attempt to access the same memory segment through another driver interface. By carefully controlling the timing of these allocations and deallocations, an attacker could potentially influence kernel memory states. Although the current impact is defined as a crash, such UAFs are critical because they corrupt the kernel's memory management state, creating opportunities for attackers to attempt heap spraying or object replacement, which could lead to bypassing kernel protection mechanisms like KASLR (Kernel Address Space Layout Randomization) or achieving arbitrary code execution if the dangling pointer can be redirected to attacker-controlled data."
}