{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89445", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.704Z", "datePublished": "2026-09-11T19:43:12.765Z", "dateUpdated": "2026-10-19T08:46:54.686Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:46:54.686Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Fix UAF in selftest IOPF reporting\n\nIOMMUFD selftest TRIGGER_IOPF borrows an attach handle from\ngroup->pasid_array without synchronizing against PASID detach,\nthen a concurrent iommu_report_device_fault() can dereference\nthat borrowed handle's domain pointer after the detach erases\nthe handle and frees the backing struct iommufd_attach_handle.\nTRIGGER_IOPF then dereferences the freed handle, causing a UAF.\n\nFix by adding a iopf_rwsem in mock_dev to follow the expected design\nof a real driver. Hold its read side across the whole\niommu_report_device_fault() call, and its write side around every\npath that attaches, detaches, or replaces a device domain.\nThis can block new reports and drains in-flight reports before an old\nattach handle or the IOPF fault parameter can be removed.\nAlso take the write side while registering a mock device, since\nit can invoke the mock driver's default-domain attach callback." } ], "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 UAF is reached only via local ioctls on /dev/iommu (or VFIO-compat /dev/vfio/vfio): IOMMU_TEST_CMD TRIGGER_IOPF calls iommu_report_device_fault() while a concurrent PASID/RID detach frees the attach handle. No network or packet-receive path exists.\nAC:L - The attacker controls both sides of the race by issuing concurrent IOMMU_TEST_OP_TRIGGER_IOPF and PASID_DETACH/REPLACE or mock-domain destroy on the same fd; iommu_attach_handle_get() does not keep the handle alive after lookup, so no victim timing or uncontrollable layout is required.\nPR:L - iommufd_fops_open() and IOMMU_TEST_CMD perform no capability checks; /dev/iommu is 0660 and MOCK_DOMAIN creates an IOPF-capable mock device without physical assignment, so an unprivileged local user with iommufd access (selftest/syzkaller kernels or VFIO/iommufd group membership) can trigger it without init-namespace root.\nUI:N - Exploitation requires no victim action; the attacker programmatically opens iommufd, creates a mock domain, attaches a PASID, and races TRIGGER_IOPF against detach through their own file descriptors and ioctls.\nS:C - The freed object is struct iommufd_attach_handle used by iommu_report_device_fault() to dispatch domain->iopf_handler and complete IOMMU page faults; pre-fix TRIGGER_IOPF also accepted any bound idev, so corrupting those handles can hijack IOMMU fault/DMA isolation across the device-assignment boundary.\nC:H - Use-after-free of iommufd_attach_handle lets an attacker reclaim the slab and control the domain pointer later read as attach_handle->domain->iopf_handler, enabling arbitrary kernel reads through the IOPF handler and fault-queue path.\nI:H - The UAF is a function-pointer dereference of domain->iopf_handler plus later handle use in iommufd_fault_iopf_handler; heap spraying yields an arbitrary write and control-flow hijack in the IOMMU fault-completion path.\nA:H - Dereferencing the freed attach handle in find_fault_handler()/iommu_report_device_fault() causes a kernel oops or panic; the UAF is reliably crashable even when not fully exploited for code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/iommu/iommufd/selftest.c" ], "versions": [ { "version": "ddee19971081b42615d62f4fdada21274708ed4d", "lessThan": "fd2e7ac94d6d813548b021473c3dddc30c8c07d1", "status": "affected", "versionType": "git" }, { "version": "ddee19971081b42615d62f4fdada21274708ed4d", "lessThan": "cab2895729516799384d48560e6fca105fb3f927", "status": "affected", "versionType": "git" }, { "version": "ddee19971081b42615d62f4fdada21274708ed4d", "lessThan": "e27e90bde68b2ab92e63ed19caad1ef57188bea0", "status": "affected", "versionType": "git" }, { "version": "ddee19971081b42615d62f4fdada21274708ed4d", "lessThan": "8c07df7cdfcf52f1ff276c588612aabc6c6b8399", "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/selftest.c" ], "versions": [ { "version": "6.11", "status": "affected" }, { "version": "0", "lessThan": "6.11", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.11", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/fd2e7ac94d6d813548b021473c3dddc30c8c07d1" }, { "url": "https://git.kernel.org/stable/c/cab2895729516799384d48560e6fca105fb3f927" }, { "url": "https://git.kernel.org/stable/c/e27e90bde68b2ab92e63ed19caad1ef57188bea0" }, { "url": "https://git.kernel.org/stable/c/8c07df7cdfcf52f1ff276c588612aabc6c6b8399" } ], "title": "iommufd: Fix UAF in selftest IOPF reporting", "x_generator": { "engine": "bippy-1.2.0" } } } }