{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89967", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.778Z", "datePublished": "2026-09-16T10:32:48.164Z", "dateUpdated": "2026-10-19T08:55:40.822Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:55:40.822Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/migrate_device: avoid out-of-bounds writes for compound folios\n\nmigrate_device_range() and migrate_device_pfns() clear the entries\nfollowing a compound folio so that the PFN arrays retain their\npage-granular representation.\n\nIf a compound folio extends beyond the end of the caller-provided range,\nthe loops clear all following folio entries without limiting them to the\nnumber of slots remaining in the npages-sized array, causing an\nout-of-bounds write.\n\nDo not proceed with a compound folio if its page-granular representation\ndoes not fit entirely in the remaining PFN array. If this happens, drop\nany reference and lock acquired for the folio, clear the remaining\nentries, and stop collecting.\n\nObserved with a KASAN x86 QEMU kernel using the HMM migrate_anon_huge_zero\nselftest. Closing /dev/hmm_dmirror0 after migrating an anonymous huge\npage to device memory exercises:\n\n dmirror_fops_release()\n -> dmirror_device_evict_chunk()\n -> migrate_device_range()" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The OOB write is in migrate_device_range()/migrate_device_pfns() on the device-private eviction path, reached from local HMM/GPU SVM (close of /dev/hmm_dmirror*, Nouveau dmem teardown, Intel Xe drm_pagemap_evict_to_ram after DRM_XE_VM_BIND), not from received network packets.\nAC:L - The attacker creates a compound device folio by migrating an anonymous THP or huge-zero page, then triggers eviction of a too-small PFN array (dmirror close/HMM_DMIRROR_RELEASE or Xe TTM eviction of a CPU_ADDR_MIRROR BO). The HMM selftest hits this deterministically; no victim timing is required.\nPR:L - Intel Xe DRM_XE_VM_BIND is DRM_RENDER_ALLOW with no capable() or DRM-master check. An unprivileged local user with typical render/video-group access to /dev/dri/renderD* can migrate a THP to device memory and force drm_pagemap_evict_to_ram.\nUI:N - The attacker performs mmap/madvise, the migrate ioctl, and eviction or close entirely in their own process. No other user or administrator needs to mount a filesystem, open a file, or otherwise interact.\nS:U - The overflow corrupts host-kernel memory adjacent to the caller-provided src_pfns kvcalloc/kvmalloc array. That is standard local privilege escalation in the same security authority, not a KVM/Xen guest-to-host escape or IOMMU/DMA bypass.\nC:H - migrate_device_* zeros every tail slot of a compound folio without clipping to npages, overflowing the PFN array by up to (folio_nr_pages-remaining) pointers (~4KB for a 2MB THP). That heap corruption can be turned into an arbitrary kernel read via overlapping objects.\nI:H - The same unbounded store is an out-of-bounds kernel write into adjacent slab/vmalloc objects. Zeroing neighboring heap metadata, pointers, or function pointers is exploitable for an arbitrary write and control-flow hijack, not a bounded integrity change.\nA:H - KASAN reports this overflow on the HMM migrate_anon_huge_zero selftest when closing /dev/hmm_dmirror0, and smashing adjacent kernel objects with zeros causes an oops or panic even without a completed exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/migrate_device.c" ], "versions": [ { "version": "a30b48bf1b244f11bf9b6d20cdccfe0c2264130c", "lessThan": "99186b185c245f5987d7f8715d5504c8d8cc04a0", "status": "affected", "versionType": "git" }, { "version": "a30b48bf1b244f11bf9b6d20cdccfe0c2264130c", "lessThan": "dc41e961a269f2ca4196e669d6d8e05480899cd4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "mm/migrate_device.c" ], "versions": [ { "version": "6.19", "status": "affected" }, { "version": "0", "lessThan": "6.19", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "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": "6.19", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/99186b185c245f5987d7f8715d5504c8d8cc04a0" }, { "url": "https://git.kernel.org/stable/c/dc41e961a269f2ca4196e669d6d8e05480899cd4" } ], "title": "mm/migrate_device: avoid out-of-bounds writes for compound folios", "x_generator": { "engine": "bippy-1.2.0" } } } }