Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-25T00:00:00 kernel: iommu/dma: Do not try to iommu_map a 0 length region in swiotlb 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-805

In the Linux kernel, the following vulnerability has been resolved: iommu/dma: Do not try to iommu_map a 0 length region in swiotlb iommu_dma_iova_link_swiotlb() processes a mapping that is unaligned in three parts, the head, middle and trailer. If the middle is empty because there are no aligned pages it will call down to iommu_map() with a 0 size which the iommupt implementation will fail as illegal. It then tries to do an error unwind and starts from the wrong spot corrupting the mapping so the eventual destruction triggers a WARN_ON. Check for 0 length and avoid mapping and use offset not 0 as the starting point to unlink. This is frequently triggered by using some kinds of thunderbolt NVMe drives that trigger forced SWIOTLB for unaligned memory. NVMe seems to pass in oddly aligned buffers for the passthrough commands from smartctl that hit this condition.

A flaw was found in the Linux kernel's input/output memory management unit (IOMMU) Direct Memory Access (DMA) subsystem, specifically within the software IOMMU bounce buffer (SWIOTLB) mechanism. This vulnerability occurs when the system attempts to map a zero-length memory region, which can be triggered by certain Thunderbolt NVMe drives passing unaligned memory buffers. This improper handling can lead to corruption of memory mappings, potentially causing system instability or a denial of service (DoS).

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-53164 https://nvd.nist.gov/vuln/detail/CVE-2026-53164 https://lore.kernel.org/linux-cve-announce/2026062550-CVE-2026-53164-88ad@gregkh/T