CVE-2026-52952

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset<br /> <br /> In __iommu_group_set_domain_internal(), concurrent domain attachments are<br /> rejected when any device in the group is recovering. This is necessary to<br /> fence concurrent attachments to a multi-device group where devices might<br /> share the same RID due to PCI DMA alias quirks, but triggers the WARN_ON in<br /> __iommu_group_set_domain_nofail().<br /> <br /> Other IOMMU_SET_DOMAIN_MUST_SUCCEED callers in detach/teardown paths, such<br /> as __iommu_group_set_core_domain and __iommu_release_dma_ownership, should<br /> not be rejected, as the domain would be freed anyway in these nofail paths<br /> while group-&gt;domain is still pointing to it. So pci_dev_reset_iommu_done()<br /> could trigger a UAF when re-attaching group-&gt;domain.<br /> <br /> Honor the IOMMU_SET_DOMAIN_MUST_SUCCEED flag, allowing the callers through<br /> the group-&gt;recovery_cnt fence, so as to update the group-&gt;domain pointer.<br /> Instead add a gdev-&gt;blocked check in the device iteration loop, to prevent<br /> any concurrent per-device detachment.