CVE Catalog

CVE-2026-64292

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.15%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel iommufd subsystem, a vulnerability was found where memory for the event queue is allocated inside a spinlock. A user can allocate a very large queue, exhausting atomic memory reserves.

Risk Assessment

An attacker can exhaust kernel atomic memory, potentially causing a denial of service (DoS) or system instability.

Recommendation

Apply the patch that moves the allocation outside the spinlock and uses GFP_NOWAIT to avoid dipping into atomic reserves.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: iommufd: Move vevent memory allocation outside spinlock The veventq memory allocation happens inside the spinlock. Given its depth is decided by the user space, this leaves a vulnerability, where userspace can allocate large queues to exhaust atomic memory reserves. Move the allocation outside the spinlock and use GFP_NOWAIT, which can fail fast under memory pressure without dipping into the GFP_ATOMIC reserves or direct-reclaiming from the threaded IRQ handler. On allocation failure, queue the lost_events_header (so userspace learns of the drop) and return -ENOMEM so the caller learns of the kernel-side memory pressure. This is intentionally distinct from the queue-overflow path, which also queues the lost_events_header but returns 0: a full queue is an expected userspace-pacing condition rather than a kernel error. A subsequent change will cap the upper bound of the veventq_depth.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS