{"id":"CVE-2026-89967","published":"2026-09-16T11:17:07.283","lastModified":"2026-09-16T15:18:20.980","description":"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()","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/99186b185c245f5987d7f8715d5504c8d8cc04a0","tags":[]},{"url":"https://git.kernel.org/stable/c/dc41e961a269f2ca4196e669d6d8e05480899cd4","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}