CVE-2026-58751 in Android
Summary
by MITRE • 09/15/2026
In multiple functions of arm-smmu-v3.c, there is a possible use-after-free due to a logic error in the code. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified within the Linux kernel driver for ARM SMMU version three represents a critical security flaw rooted in improper memory management and race condition handling during device stream mapping operations. Specifically, this issue manifests across multiple functions in the arm-smmu-v3.c source file where reference counting mechanisms fail to properly synchronize with object lifecycle states. When an IOMMU domain is detached or reconfigured, certain internal structures representing stream entries are freed prematurely while still being referenced by concurrent hardware translation contexts or software state machines that have not yet completed their execution cycles. This logic error results in a use-after-free condition where the kernel attempts to access memory regions that have already been returned to the general allocator pool and potentially reallocated for unrelated purposes.
From a technical perspective, this flaw stems from insufficient locking granularity or missing synchronization primitives when transitioning between different SMMU operational states. The ARM System Memory Management Unit is responsible for translating device bus addresses to physical addresses, acting as a critical security boundary that isolates devices from direct memory access outside their assigned domains. When the driver incorrectly frees stream context structures before ensuring all pending translation requests are flushed and acknowledged by the hardware, it creates a window of opportunity where stale pointers remain valid in software but point to freed or reused kernel memory. This scenario is particularly dangerous because SMMU operations often occur at high frequency during device initialization, hot-plug events, or virtual machine migration scenarios involving passthrough devices.
The operational impact of this vulnerability allows for local privilege escalation from a standard user context to that of the system with full execution privileges. An attacker who has gained access to the target system can exploit this race condition by triggering rapid IOMMU domain changes while simultaneously manipulating memory allocation patterns to control the contents of the freed memory region. By carefully crafting heap spray techniques or leveraging other kernel vulnerabilities, an adversary could overwrite critical function pointers or data structures within the reused memory space. Upon dereference, these maliciously crafted values would be executed in ring zero, effectively bypassing all user-space security controls and granting complete administrative control over the host system.
This vulnerability aligns with CWE-416 which describes use-after-free errors resulting from improper handling of object lifecycles after deallocation. In terms of offensive cybersecurity frameworks such as MITRE ATT&CK, this flaw facilitates privilege escalation techniques categorized under Tactic TA0004 and specifically relates to process injection or kernel module exploitation strategies where attackers leverage memory corruption bugs to gain elevated access without requiring user interaction. The absence of required user input makes this vulnerability particularly severe in multi-tenant environments such as cloud infrastructure or containerized workloads where untrusted processes may attempt to interact with hardware virtualization features like SR-IOV devices assigned directly to guest VMs.
Mitigation strategies must focus on both immediate patching and long-term architectural improvements within the kernel driver codebase. The primary remediation involves applying vendor-supplied security patches that address the reference counting logic in arm-smmu-v3.c, ensuring that stream context structures are only freed after all associated hardware contexts have been properly invalidated and software state machines have reached a quiescent point. Developers should implement strict locking mechanisms around domain detachment sequences to prevent concurrent access during critical transitions. Additionally enabling kernel hardening features such as KASAN for debugging purposes in development environments can help detect similar issues early in the lifecycle. For production systems, restricting device assignment capabilities through IOMMU group isolation policies and limiting which users or containers can request direct hardware access significantly reduces the attack surface available to potential exploiters seeking to trigger this race condition.