CVE-2026-52952
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk3th percentile — higher than 3% of all known CVEs
Summary
A vulnerability in the Linux kernel IOMMU subsystem causes a WARN_ON in __iommu_group_set_domain_nofail() due to reset. Incorrect blocking of concurrent domain attachments during group recovery can lead to a use-after-free (UAF) in detach/teardown paths.
Risk Assessment
The risk includes potential use-after-free (UAF) during PCI device reset, which could lead to system crash or local privilege escalation.
Recommendation
Immediately update the Linux kernel to a version containing the fix that corrects the __iommu_group_set_domain_nofail() logic and adds a gdev->blocked check in the device iteration loop.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset In __iommu_group_set_domain_internal(), concurrent domain attachments are rejected when any device in the group is recovering. This is necessary to fence concurrent attachments to a multi-device group where devices might share the same RID due to PCI DMA alias quirks, but triggers the WARN_ON in __iommu_group_set_domain_nofail(). Other IOMMU_SET_DOMAIN_MUST_SUCCEED callers in detach/teardown paths, such as __iommu_group_set_core_domain and __iommu_release_dma_ownership, should not be rejected, as the domain would be freed anyway in these nofail paths while group->domain is still pointing to it. So pci_dev_reset_iommu_done() could trigger a UAF when re-attaching group->domain. Honor the IOMMU_SET_DOMAIN_MUST_SUCCEED flag, allowing the callers through the group->recovery_cnt fence, so as to update the group->domain pointer. Instead add a gdev->blocked check in the device iteration loop, to prevent any concurrent per-device detachment.