CVE-2026-64071 : Detail

CVE-2026-64071

7.8
/
High
Memory Corruption
Local
2026-07-19
16h17 +00:00
2026-09-03
14h54 +00:00
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CVE Descriptions

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix use-after-free in nvme_free_host_mem() nvme_free_host_mem() frees dev->hmb_sgt via dma_free_noncontiguous() but never clears the pointer afterward. This leads to a use-after-free if nvme_free_host_mem() is called twice in the same error path. This can happen during nvme_probe() when nvme_setup_host_mem() succeeds in allocating the HMB (setting dev->hmb_sgt) but nvme_set_host_mem() fails with an I/O error: nvme_setup_host_mem() nvme_alloc_host_mem_single() -> sets dev->hmb_sgt nvme_set_host_mem() -> fails with -EIO nvme_free_host_mem() -> frees hmb_sgt, but does NOT NULL it return error nvme_probe() error path: nvme_free_host_mem() -> dev->hmb_sgt is stale, use-after-free The second call dereferences the freed sgt, causing a NULL pointer dereference in iommu_dma_free_noncontiguous() when it accesses sgt->sgl->dma_address (the backing memory has been freed and zeroed). This is reproducible on Thunderbolt-attached NVMe devices (e.g., OWC Envoy Express behind a Dell WD22TB4 dock) where the device intermittently returns I/O errors during HMB setup due to PCIe link instability. BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:iommu_dma_free_noncontiguous+0x22/0x80 Call Trace: dma_free_noncontiguous+0x3b/0x130 nvme_free_host_mem+0x30/0xf0 [nvme] nvme_probe.cold+0xcc/0x275 [nvme] local_pci_probe+0x43/0xa0 pci_device_probe+0xeea/0x290 really_probe+0xf9/0x3b0 __driver_probe_device+0x8b/0x170 driver_probe_device+0x24/0xd0 __driver_attach_async_helper+0x6b/0x110 async_run_entry_fn+0x37/0x170 process_one_work+0x1ac/0x3d0 worker_thread+0x1b8/0x360 kthread+0xf7/0x130 ret_from_fork+0x2d8/0x3a0 ret_from_fork_asm+0x1a/0x30 Fix this by setting dev->hmb_sgt to NULL after freeing it, so the second call takes the multi-descriptor path which safely handles the already-cleaned-up state.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-416 Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 7.8 HIGH CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Local

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities.

Attack Complexity

This metric describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is a total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

nvd@nist.gov

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (including) 6.13 To (excluding) 6.18.34

Linux>>Linux_kernel >> Version From (including) 6.19 To (excluding) 7.0.11

Linux>>Linux_kernel >> Version 7.1

Linux>>Linux_kernel >> Version 7.1

Linux>>Linux_kernel >> Version 7.1

References