CVE-2026-80633

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80633", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.776Z", "datePublished": "2026-08-28T06:48:48.372Z", "dateUpdated": "2026-08-29T06:21:32.731Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-29T06:21:32.731Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Take dma_resv lock before dma_buf_unpin() in release path\n\ndma_buf_unpin() requires the caller to hold the exporter's dma_resv\nlock:\n\n void dma_buf_unpin(struct dma_buf_attachment *attach)\n {\n ...\n dma_resv_assert_held(dmabuf->resv);\n ...\n }\n\niopt_release_pages() calls dma_buf_unpin() without taking that lock,\nso every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases\nthe last reference on a DMABUF-backed iopt_pages triggers a WARN.\nThis was hit while running tools/testing/selftests/iommu/iommufd:\n\n WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70\n RIP: 0010:dma_buf_unpin+0x62/0x70\n Call Trace:\n <TASK>\n dma_buf_unpin+0x62/0x70\n iopt_release_pages+0xe4/0x190\n iopt_unmap_iova_range+0x1c7/0x290\n iopt_unmap_all+0x1a/0x30\n iommufd_ioas_destroy+0x1d/0x50\n iommufd_fops_release+0x93/0x150\n __fput+0xfc/0x2c0\n __x64_sys_close+0x3d/0x80\n do_syscall_64+0x65/0x180\n </TASK>\n\nTake the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),\nmatching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the\nreservation lock internally, so it must remain outside the locked region."}], "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 bug is reached only via local syscalls on /dev/iommu or VFIO-compat iommufd: open, IOMMU_IOAS_MAP_FILE with a dma-buf fd, then IOMMU_IOAS_UNMAP/close triggers iopt_release_pages()->dma_buf_unpin(); no network or packet handler is involved.\nAC:L - Every teardown of the last dma-buf-backed iopt_pages deterministically hits dma_buf_unpin() without dma_resv; an attacker also controls concurrent invalidate/revoke via IOMMU_IOAS_UNMAP and dma_buf_invalidate_mappings (selftest revoke or VFIO PCI dmabuf revoke).\nPR:L - No init-namespace root or special capability is required for the IOAS map/unmap path once a process can open iommufd (0660) and hold a compatible dma-buf fd, as in cloud GPU/VFIO passthrough tenants or iommufd selftests.\nUI:N - Exploitation requires no victim interaction; the attacker programmatically creates the IOAS dma-buf mapping and drives unmap/close and optional concurrent revoke through their own file descriptors and ioctl calls.\nS:C - Missing dma_resv locking during dma-buf unpin/detach races dma_buf_invalidate_mappings and can leave stale IOMMU IOVA-to-physical mappings or permit buffer movement while DMA views remain, breaking the IOMMU/DMA isolation boundary.\nC:H - Concurrent dma_resv-protected invalidation during unpin without the reservation lock can race teardown of iopt_pages/dmabuf attachments and yield kernel heap use-after-free or stale mapping visibility exploitable for arbitrary kernel memory read.\nI:H - Racing unpin without dma_resv against invalidate/revoke can leave IOMMU page tables pointing at repinned/moved exporter pages, giving a device DMA write primitive to attacker-influenced physical memory and enabling control-flow corruption.\nA:H - The missing lock triggers dma_resv_assert_held WARN on every dma-buf IOAS unmap/destroy (reproduced in iommufd selftests), and concurrent teardown races can provoke kernel oops/panic or wedge GPU/VFIO+iommufd workloads."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/iommu/iommufd/pages.c"], "versions": [{"version": "8c5f9645c3893f0db679d9affe4fe4e665b990dd", "lessThan": "cc69d0332421fd2943b66dbe5e597bf4fd5af126", "status": "affected", "versionType": "git"}, {"version": "8c5f9645c3893f0db679d9affe4fe4e665b990dd", "lessThan": "e745cd2c749e557c14a15ac931761c3f58c24489", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/iommu/iommufd/pages.c"], "versions": [{"version": "7.1", "status": "affected"}, {"version": "0", "lessThan": "7.1", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/cc69d0332421fd2943b66dbe5e597bf4fd5af126"}, {"url": "https://git.kernel.org/stable/c/e745cd2c749e557c14a15ac931761c3f58c24489"}], "title": "iommufd: Take dma_resv lock before dma_buf_unpin() in release path", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/iommu/iommufd/pages.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "cc69d0332421fd2943b66dbe5e597bf4fd5af126", "status": "affected", "version": "8c5f9645c3893f0db679d9affe4fe4e665b990dd", "versionType": "git"}, {"lessThan": "e745cd2c749e557c14a15ac931761c3f58c24489", "status": "affected", "version": "8c5f9645c3893f0db679d9affe4fe4e665b990dd", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/iommu/iommufd/pages.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.1"}, {"lessThan": "7.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Take dma_resv lock before dma_buf_unpin() in release path\n\ndma_buf_unpin() requires the caller to hold the exporter's dma_resv\nlock:\n\n void dma_buf_unpin(struct dma_buf_attachment *attach)\n {\n ...\n dma_resv_assert_held(dmabuf->resv);\n ...\n }\n\niopt_release_pages() calls dma_buf_unpin() without taking that lock,\nso every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases\nthe last reference on a DMABUF-backed iopt_pages triggers a WARN.\nThis was hit while running tools/testing/selftests/iommu/iommufd:\n\n WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70\n RIP: 0010:dma_buf_unpin+0x62/0x70\n Call Trace:\n <TASK>\n dma_buf_unpin+0x62/0x70\n iopt_release_pages+0xe4/0x190\n iopt_unmap_iova_range+0x1c7/0x290\n iopt_unmap_all+0x1a/0x30\n iommufd_ioas_destroy+0x1d/0x50\n iommufd_fops_release+0x93/0x150\n __fput+0xfc/0x2c0\n __x64_sys_close+0x3d/0x80\n do_syscall_64+0x65/0x180\n </TASK>\n\nTake the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),\nmatching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the\nreservation lock internally, so it must remain outside the locked region."}], "id": "CVE-2026-80633", "lastModified": "2026-08-29T07:16:47.320", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.0, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-28T08:16:48.200", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cc69d0332421fd2943b66dbe5e597bf4fd5af126"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e745cd2c749e557c14a15ac931761c3f58c24489"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: iommufd: Take dma_resv lock before dma_buf_unpin() in release path", "id": "2525504", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2525504"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-414", "details": ["In the Linux kernel, the following vulnerability has been resolved:\niommufd: Take dma_resv lock before dma_buf_unpin() in release path\ndma_buf_unpin() requires the caller to hold the exporter's dma_resv\nlock:\nvoid dma_buf_unpin(struct dma_buf_attachment *attach)\n{\n...\ndma_resv_assert_held(dmabuf->resv);\n...\n}\niopt_release_pages() calls dma_buf_unpin() without taking that lock,\nso every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases\nthe last reference on a DMABUF-backed iopt_pages triggers a WARN.\nThis was hit while running tools/testing/selftests/iommu/iommufd:\nWARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70\nRIP: 0010:dma_buf_unpin+0x62/0x70\nCall Trace:\n<TASK>\ndma_buf_unpin+0x62/0x70\niopt_release_pages+0xe4/0x190\niopt_unmap_iova_range+0x1c7/0x290\niopt_unmap_all+0x1a/0x30\niommufd_ioas_destroy+0x1d/0x50\niommufd_fops_release+0x93/0x150\n__fput+0xfc/0x2c0\n__x64_sys_close+0x3d/0x80\ndo_syscall_64+0x65/0x180\n</TASK>\nTake the dma_resv lock around dma_buf_unpin() in iopt_release_pages(),\nmatching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the\nreservation lock internally, so it must remain outside the locked region.", "A flaw was found in the Linux kernel's iommufd component. A local user could trigger a kernel warning by releasing the last reference on a Direct Memory Access Buffer (DMABUF)-backed IOMMU page table without holding the necessary `dma_resv` lock. This missing lock operation can lead to system instability or a denial of service."], "name": "CVE-2026-80633", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-28T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-80633\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-80633\nhttps://lore.kernel.org/linux-cve-announce/2026082839-CVE-2026-80633-da07@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8c5f9645c3893f0db679d9affe4fe4e665b990dd,cc69d0332421fd2943b66dbe5e597bf4fd5af126)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8c5f9645c3893f0db679d9affe4fe4e665b990dd,e745cd2c749e557c14a15ac931761c3f58c24489)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "7.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-28T09:30:18.290673+00:00", "updated": "2026-08-31T16:00:06.139300+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}