{"id":"CVE-2026-52952","state":"PUBLISHED","title":"iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset\n\nIn __iommu_group_set_domain_internal(), concurrent domain attachments are\nrejected when any device in the group is recovering. This is necessary to\nfence concurrent attachments to a multi-device group where devices might\nshare the same RID due to PCI DMA alias quirks, but triggers the WARN_ON in\n__iommu_group_set_domain_nofail().\n\nOther IOMMU_SET_DOMAIN_MUST_SUCCEED callers in detach/teardown paths, such\nas __iommu_group_set_core_domain and __iommu_release_dma_ownership, should\nnot be rejected, as the domain would be freed anyway in these nofail paths\nwhile group->domain is still pointing to it. So pci_dev_reset_iommu_done()\ncould trigger a UAF when re-attaching group->domain.\n\nHonor the IOMMU_SET_DOMAIN_MUST_SUCCEED flag, allowing the callers through\nthe group->recovery_cnt fence, so as to update the group->domain pointer.\nInstead add a gdev->blocked check in the device iteration loop, to prevent\nany concurrent per-device detachment.","publishedAt":"2026-06-24T16:28:35.247Z","updatedAt":"2026-08-05T12:32:02.035Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c279e83953d937470f8a6e69b69f62608714f13f","status":"affected","lessThan":"8fc289e809f3eb7e36cadc4684ab6fad747a5a93","versionType":"git"},{"version":"c279e83953d937470f8a6e69b69f62608714f13f","status":"affected","lessThan":"5474e6e17a262db45c60575c73f70210f5c7001f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommu.c"]}],"references":["https://git.kernel.org/stable/c/8fc289e809f3eb7e36cadc4684ab6fad747a5a93","https://git.kernel.org/stable/c/5474e6e17a262db45c60575c73f70210f5c7001f","https://access.redhat.com/security/cve/CVE-2026-52952","https://bugzilla.redhat.com/show_bug.cgi?id=2492422","https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52952.json"],"weaknesses":["CWE-825"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52952.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52952","state":"PUBLISHED","datePublished":"2026-06-24T16:28:35.247Z","dateUpdated":"2026-08-05T12:32:02.035Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.372Z"},"containers":{"cna":{"title":"iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset\n\nIn __iommu_group_set_domain_internal(), concurrent domain attachments are\nrejected when any device in the group is recovering. This is necessary to\nfence concurrent attachments to a multi-device group where devices might\nshare the same RID due to PCI DMA alias quirks, but triggers the WARN_ON in\n__iommu_group_set_domain_nofail().\n\nOther IOMMU_SET_DOMAIN_MUST_SUCCEED callers in detach/teardown paths, such\nas __iommu_group_set_core_domain and __iommu_release_dma_ownership, should\nnot be rejected, as the domain would be freed anyway in these nofail paths\nwhile group->domain is still pointing to it. So pci_dev_reset_iommu_done()\ncould trigger a UAF when re-attaching group->domain.\n\nHonor the IOMMU_SET_DOMAIN_MUST_SUCCEED flag, allowing the callers through\nthe group->recovery_cnt fence, so as to update the group->domain pointer.\nInstead add a gdev->blocked check in the device iteration loop, to prevent\nany concurrent per-device detachment."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c279e83953d937470f8a6e69b69f62608714f13f","status":"affected","lessThan":"8fc289e809f3eb7e36cadc4684ab6fad747a5a93","versionType":"git"},{"version":"c279e83953d937470f8a6e69b69f62608714f13f","status":"affected","lessThan":"5474e6e17a262db45c60575c73f70210f5c7001f","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommu.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.0","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/iommu/iommu.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8fc289e809f3eb7e36cadc4684ab6fad747a5a93"},{"url":"https://git.kernel.org/stable/c/5474e6e17a262db45c60575c73f70210f5c7001f"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable IOMMU recovery path is reached through local PCI/VFIO/IOMMUFD operations such as device reset and domain attach/detach, not by remote packets or physical insertion.\nAC:L - A caller with access to the VFIO/IOMMUFD device can create the reset window and concurrently detach/release the domain; the race window is attacker-influenced and does not depend on rare external conditions.\nPR:L - Exploitation requires local access to an assigned VFIO/IOMMUFD-capable device or equivalent device node permissions, but not necessarily full init-namespace root once the device is delegated.\nUI:N - No victim action is needed after the attacker has the local device access; the attacker can issue the reset and detach operations directly.\nS:C - The stale freed IOMMU domain can affect DMA/IOMMU isolation, allowing impact beyond the attacker's assigned device/IOMMU context and into host-protected resources.\nC:H - The bug can leave `group->domain` pointing to a freed IOMMU domain and then reattach through it, a use-after-free that can plausibly be shaped into disclosure of protected host memory.\nI:H - Reusing a freed IOMMU domain during device reattachment can corrupt IOMMU state or subvert DMA mappings, giving a plausible path to arbitrary modification of protected memory.\nA:H - At minimum the stale domain dereference and WARN/UAF path can crash or destabilize the kernel during reset recovery."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:32:02.035Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"kernel: iommu: Fix WARN_ON in __iommu_group_set_domain_nofail() due to reset","descriptions":[{"lang":"en","value":"A flaw was found in the Linux kernel's Input/Output Memory Management Unit (IOMMU) subsystem, which manages how devices access system memory. A race condition, a situation where multiple operations occur in an unpredictable order, exists during device recovery when multiple memory domains are being attached concurrently. This can lead to a Use-After-Free (UAF) vulnerability, where the system attempts to use memory that has already been released, potentially allowing a local attacker to execute unauthorized code or cause the system to crash (denial of service)."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"kernel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"kernel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"kernel-rt","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-52952","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492422","name":"RHBZ#2492422","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52952.json","tags":["x_sadp-csaf-vex"]}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-825","description":"Expired Pointer Dereference","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat-SADP","orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","dateUpdated":"2026-07-15T00:45:50.476Z"},"datePublic":"2026-06-24T00:00:00.000Z","timeline":[{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Made public."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"}}]}}}