CVE-2026-53300

Status: AnalyzedHigh (7.8)—

In the Linux kernel, the following vulnerability has been resolved:

net: enetc: fix NTMP DMA use-after-free issue

The AI-generated review reported a potential DMA use-after-free issue [1]. If netc_xmit_ntmp_cmd() times out and returns an error, the pending command is not explicitly aborted, while ntmp_free_data_mem() unconditionally frees the DMA buffer. If the buffer has already been reallocated elsewhere, this may lead to silent memory corruption. Because the hardware eventually processes the pending command and perform a DMA write of the response to the physical address of the freed buffer.

To resolve this issue, this patch does the following modifications:

Read full descriptionShow less

1. Convert cbdr->ring_lock from a spinlock to a mutex

The lock was originally a spinlock in case NTMP operations might be invoked from atomic context. After downstream support for all NTMP tables, no such usage has materialized. A mutex lock is now required because the driver now needs to reclaim used BDs and release associated DMA memory within the lock's context, while dma_free_coherent() might sleep.

2. Introduce software command BD (struct netc_swcbd)

The hardware write-back overwrites the addr and len fields of the BD, so the driver cannot rely on the hardware BD to free the associated DMA memory. The driver now maintains a software shadow BD storing the DMA buffer pointer, DMA address, and size. And netc_xmit_ntmp_cmd() only reclaims older BDs when the number of used BDs reaches NETC_CBDR_CLEAN_WORK (16). The software BD enables correct DMA memory release. With this, struct ntmp_dma_buf and ntmp_free_data_mem() are no longer needed and are removed.

3. Require callers to hold ring_lock across netc_xmit_ntmp_cmd()

netc_xmit_ntmp_cmd() releases the ring_lock before the caller finishes consuming the response. At this point, if a concurrent thread submits a new command, it may trigger ntmp_clean_cbdr() and free the DMA buffer while it is still in use. Move ring_lock ownership to the caller to ensure the response buffer cannot be reclaimed prematurely. So the helpers ntmp_select_and_lock_cbdr() and ntmp_unlock_cbdr() are added.

These changes eliminate the DMA use-after-free condition and ensure safe and consistent BD reclamation and DMA buffer lifecycle management.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base score: 7.8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.17%
Percentile among all scored CVEs: 6
Score date: 10/3/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Primary impactT1565.001 Stored Data Manipulationimpact80 %
Secondary impactT1499.004 Application or System Exploitationimpact70 %

Acceso local (AV:L) sin interacción de usuario permite a atacante local con privilegios (PR:L) explotar use-after-free en DMA del kernel para corrupción de memoria silenciosa (impacto integridad) y potencial denegación de servicio.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Threat Intelligence Program Restrict File and Directory Permissions Remote Data Storage Filter Network Traffic Execution Prevention Encrypt Sensitive Information

Affected technologies (1)

Linux — Linux Kernel

CWEs

CWE-416

References

Raw JSON (NVD)

Show

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    }
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  "lastModified": "2026-07-08T03:38:42.627",
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