CVE-2026-59043 in Android
Summary
by MITRE • 11/02/2026
In arm_lpae_split_blk_unmap of io-pgtable-arm-common.c, there is a possible memory corruption due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified in the arm_lpae_split_blk_unmap function within io-pgtable-arm-common.c represents a critical concurrency flaw rooted in the complex memory management subsystems of ARM architectures utilizing Large Address and Memory (LAM) or similar page table structures. This specific race condition occurs during the process of unmapping memory blocks, where the system attempts to split large block mappings into smaller page-level entries to facilitate precise deallocation or modification. The core technical flaw lies in the lack of proper synchronization mechanisms when multiple threads or interrupt contexts attempt to access and modify the same page table structures concurrently. Specifically, the function fails to adequately serialize operations that involve reading current mapping states while simultaneously preparing for structural changes, leading to a window where inconsistent data can be written back to memory. This inconsistency manifests as heap-based buffer overflows or use-after-free scenarios within the kernel's internal data structures, which are typically protected by higher privilege levels than user-space applications.
From an operational impact perspective, this vulnerability allows for local escalation of privilege without requiring any additional execution privileges from the attacker beyond basic access to a process that can trigger memory unmapping operations. Since no user interaction is required and no special execution privileges such as root or administrator rights are needed initially, the attack surface is significantly broadened. An unprivileged user-space application could potentially exploit this race condition by rapidly allocating and freeing memory in specific patterns designed to manipulate the timing of page table updates. By carefully crafting these operations, an attacker can corrupt critical kernel data structures, thereby gaining control over execution flow or arbitrary read-write capabilities within the kernel space. This effectively bypasses standard isolation boundaries between user mode and supervisor mode, granting full system control equivalent to that of a root-level account.
The classification of this vulnerability aligns closely with CWE-362, which describes concurrent access resulting in race conditions, particularly when shared resources are accessed without proper locking or atomic operations. Furthermore, the exploitation technique maps directly to MITRE ATT&CK techniques related to privilege escalation via kernel exploits and memory corruption vulnerabilities such as CWE-120 (Buffer Copy without Checking Size of Input) or CWE-416 (Use After Free), depending on the specific manifestation of the race condition in different system states. The absence of adequate synchronization primitives like spinlocks or mutexes around critical sections involving page table manipulation is a common pitfall in low-level memory management code, especially when optimizing for performance under high concurrency loads typical in modern multi-core ARM processors.
Mitigation strategies must focus on enforcing strict serialization of page table modifications to prevent concurrent access from leading to inconsistent states. Implementing robust locking mechanisms around the arm_lpae_split_blk_unmap function and related helper routines is essential to ensure that only one thread can modify a specific set of page tables at any given time. Additionally, developers should consider using atomic operations for flag checks and updates within these critical sections to reduce lock contention while maintaining consistency. On the defensive side, systems running affected kernels should apply vendor-provided security patches as soon as they become available. For environments where patching is not immediately feasible, enabling Kernel Address Space Layout Randomization (KASLR) can increase the difficulty of exploitation by obscuring memory addresses, although it does not prevent the underlying corruption itself. Regular auditing of kernel code for concurrency issues and employing static analysis tools designed to detect race conditions in low-level system components are also recommended practices to identify similar vulnerabilities before they reach production environments.