CVE-2026-53164

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