CVE-2025-40006

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-40006", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.151Z", "datePublished": "2025-10-20T15:26:53.097Z", "dateUpdated": "2026-08-05T12:07:03.344Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:03.344Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb: fix folio is still mapped when deleted\n\nMigration may be raced with fallocating hole. remove_inode_single_folio\nwill unmap the folio if the folio is still mapped. However, it's called\nwithout folio lock. If the folio is migrated and the mapped pte has been\nconverted to migration entry, folio_mapped() returns false, and won't\nunmap it. Due to extra refcount held by remove_inode_single_folio,\nmigration fails, restores migration entry to normal pte, and the folio is\nmapped again. As a result, we triggered BUG in filemap_unaccount_folio.\n\nThe log is as follows:\n BUG: Bad page cache in process hugetlb pfn:156c00\n page: refcount:515 mapcount:0 mapping:0000000099fef6e1 index:0x0 pfn:0x156c00\n head: order:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0\n aops:hugetlbfs_aops ino:dcc dentry name(?):\"my_hugepage_file\"\n flags: 0x17ffffc00000c1(locked|waiters|head|node=0|zone=2|lastcpupid=0x1fffff)\n page_type: f4(hugetlb)\n page dumped because: still mapped when deleted\n CPU: 1 UID: 0 PID: 395 Comm: hugetlb Not tainted 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NONE\n Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015\n Call Trace:\n <TASK>\n dump_stack_lvl+0x4f/0x70\n filemap_unaccount_folio+0xc4/0x1c0\n __filemap_remove_folio+0x38/0x1c0\n filemap_remove_folio+0x41/0xd0\n remove_inode_hugepages+0x142/0x250\n hugetlbfs_fallocate+0x471/0x5a0\n vfs_fallocate+0x149/0x380\n\nHold folio lock before checking if the folio is mapped to avold race with\nmigration."}], "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 - Exploitation requires local syscalls only \u2014 `memfd_create(MFD_HUGETLB)`/`mmap` plus `fallocate(FALLOC_FL_PUNCH_HOLE)` racing against `mbind`/`move_pages`. There is no network-reachable path into hugetlbfs fallocate.\nAC:L - The attacker controls both sides of the race with its own threads \u2014 one looping on punch-hole, the other looping on NUMA migration of the same mapping \u2014 and can retry indefinitely at no cost until the window is hit. Per race-condition guidance, attacker-driven races are Low.\nPR:L - `memfd_create(MFD_HUGETLB)` uses HUGETLB_ANONHUGE_INODE and bypasses the `can_do_hugetlb_shm()`/CAP_IPC_LOCK check entirely, and `MPOL_MF_MOVE` on one's own address space needs no capability, so an ordinary unprivileged local user can reach the whole path.\nUI:N - The attacking process performs every step itself; no victim action, mount, or file open by another user is needed.\nS:U - The vulnerable code and the corrupted resources are both in the host kernel's memory management, so the impact stays within a single security authority despite the severity.\nC:H - The huge page is unlinked from the page cache with its `mapping` cleared while the attacker retains writable PTEs, and hugetlb folios are explicitly excluded from `filemap_unaccount_folio()`'s recovery heuristic \u2014 leaving a stale mapping to a 2MB page the kernel may recycle to another process, container, or hugepage-backed KVM guest, yielding arbitrary read of that memory.\nI:H - The same stale writable mapping gives an arbitrary-write primitive over whatever the kernel later places in that recycled huge page, and the hugetlb reserve/subpool counters are decremented for a page still in use, corrupting pool accounting \u2014 memory corruption of this class is leveragable for control-flow hijack.\nA:H - The bug's directly observed symptom is the `BUG: Bad page cache ... still mapped when deleted` report, which is a hard `VM_BUG_ON_FOLIO()` panic under CONFIG_DEBUG_VM and a `TAINT_BAD_PAGE` plus unrecoverable page-cache/hugetlb-pool corruption otherwise, repeatable at will by an unprivileged user."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/hugetlbfs/inode.c"], "versions": [{"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "bc1c9ce8aeff45318332035dbef9713fb9e982d7", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "91f548e920fbf8be3f285bfa3fa045ae017e836d", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "3e851448078f5b01f6264915df3cfef75e323a12", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "c9c2a51f91aea70e89b496cac360cd795a2b3c26", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "910d7749346c4b0acdc6e4adfdc4a9984281a206", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "21ee79ce938127f88fe07e409c1817f477dbe7ea", "status": "affected", "versionType": "git"}, {"version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "lessThan": "7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/hugetlbfs/inode.c"], "versions": [{"version": "4.5", "status": "affected"}, {"version": "0", "lessThan": "4.5", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.300", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.245", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.194", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.155", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.109", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.50", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.10", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17", "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": "4.5", "versionEndExcluding": "5.4.300"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "5.10.245"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "5.15.194"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.1.155"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.6.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.12.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.16.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.5", "versionEndExcluding": "6.17"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bc1c9ce8aeff45318332035dbef9713fb9e982d7"}, {"url": "https://git.kernel.org/stable/c/91f548e920fbf8be3f285bfa3fa045ae017e836d"}, {"url": "https://git.kernel.org/stable/c/3e851448078f5b01f6264915df3cfef75e323a12"}, {"url": "https://git.kernel.org/stable/c/c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39"}, {"url": "https://git.kernel.org/stable/c/c9c2a51f91aea70e89b496cac360cd795a2b3c26"}, {"url": "https://git.kernel.org/stable/c/910d7749346c4b0acdc6e4adfdc4a9984281a206"}, {"url": "https://git.kernel.org/stable/c/21ee79ce938127f88fe07e409c1817f477dbe7ea"}, {"url": "https://git.kernel.org/stable/c/7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7"}], "title": "mm/hugetlb: fix folio is still mapped when deleted", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/hugetlbfs/inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bc1c9ce8aeff45318332035dbef9713fb9e982d7", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "91f548e920fbf8be3f285bfa3fa045ae017e836d", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "3e851448078f5b01f6264915df3cfef75e323a12", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "c9c2a51f91aea70e89b496cac360cd795a2b3c26", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "910d7749346c4b0acdc6e4adfdc4a9984281a206", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "21ee79ce938127f88fe07e409c1817f477dbe7ea", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}, {"lessThan": "7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7", "status": "affected", "version": "4aae8d1c051ea00b456da6811bc36d1f69de5445", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/hugetlbfs/inode.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "4.5"}, {"lessThan": "4.5", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.4.*", "status": "unaffected", "version": "5.4.300", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.245", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.194", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.155", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.109", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.50", "versionType": "semver"}, {"lessThanOrEqual": "6.16.*", "status": "unaffected", "version": "6.16.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.17", "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\nmm/hugetlb: fix folio is still mapped when deleted\n\nMigration may be raced with fallocating hole. remove_inode_single_folio\nwill unmap the folio if the folio is still mapped. However, it's called\nwithout folio lock. If the folio is migrated and the mapped pte has been\nconverted to migration entry, folio_mapped() returns false, and won't\nunmap it. Due to extra refcount held by remove_inode_single_folio,\nmigration fails, restores migration entry to normal pte, and the folio is\nmapped again. As a result, we triggered BUG in filemap_unaccount_folio.\n\nThe log is as follows:\n BUG: Bad page cache in process hugetlb pfn:156c00\n page: refcount:515 mapcount:0 mapping:0000000099fef6e1 index:0x0 pfn:0x156c00\n head: order:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0\n aops:hugetlbfs_aops ino:dcc dentry name(?):\"my_hugepage_file\"\n flags: 0x17ffffc00000c1(locked|waiters|head|node=0|zone=2|lastcpupid=0x1fffff)\n page_type: f4(hugetlb)\n page dumped because: still mapped when deleted\n CPU: 1 UID: 0 PID: 395 Comm: hugetlb Not tainted 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NONE\n Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015\n Call Trace:\n <TASK>\n dump_stack_lvl+0x4f/0x70\n filemap_unaccount_folio+0xc4/0x1c0\n __filemap_remove_folio+0x38/0x1c0\n filemap_remove_folio+0x41/0xd0\n remove_inode_hugepages+0x142/0x250\n hugetlbfs_fallocate+0x471/0x5a0\n vfs_fallocate+0x149/0x380\n\nHold folio lock before checking if the folio is mapped to avold race with\nmigration."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmm/hugetlb: corregir el folio sigue mapeado cuando se elimina\n\nLa migraci\u00f3n puede tener una condici\u00f3n de carrera con la asignaci\u00f3n de un hueco. remove_inode_single_folio desmapear\u00e1 el folio si el folio sigue mapeado. Sin embargo, se llama sin el bloqueo del folio. Si el folio es migrado y la pte mapeada ha sido convertida a una entrada de migraci\u00f3n, folio_mapped() devuelve falso, y no lo desmapear\u00e1. Debido a un refcount extra mantenido por remove_inode_single_folio, la migraci\u00f3n falla, restaura la entrada de migraci\u00f3n a una pte normal, y el folio es mapeado de nuevo. Como resultado, activamos un BUG en filemap_unaccount_folio.\n\nEl registro es el siguiente:\nBUG: Cach\u00e9 de p\u00e1gina incorrecta en el proceso hugetlb pfn:156c00\np\u00e1gina: refcount:515 mapcount:0 mapeo:0000000099fef6e1 \u00edndice:0x0 pfn:0x156c00\ncabecera: orden:9 mapcount:1 entire_mapcount:1 nr_pages_mapped:0 pincount:0\naops:hugetlbfs_aops ino:dcc nombre dentry(?):'my_hugepage_file'\nflags: 0x17ffffc00000c1(bloqueado|esperando|cabecera|nodo=0|zona=2|lastcpupid=0x1fffff)\ntipo_p\u00e1gina: f4(hugetlb)\np\u00e1gina volcada porque: sigue mapeada cuando se elimina\nCPU: 1 UID: 0 PID: 395 Comm: hugetlb No contaminado 6.17.0-rc5-00044-g7aac71907bde-dirty #484 NINGUNO\nNombre del hardware: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015\nTraza de Llamada:\n <TAREA>\n dump_stack_lvl+0x4f/0x70\n filemap_unaccount_folio+0xc4/0x1c0\n __filemap_remove_folio+0x38/0x1c0\n filemap_remove_folio+0x41/0xd0\n remove_inode_hugepages+0x142/0x250\n hugetlbfs_fallocate+0x471/0x5a0\n vfs_fallocate+0x149/0x380\n\nMantener el bloqueo del folio antes de comprobar si el folio est\u00e1 mapeado para evitar una condici\u00f3n de carrera con la migraci\u00f3n."}], "id": "CVE-2025-40006", "lastModified": "2026-10-19T21:10:00.160", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2025-10-20T16:15:37.240", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/21ee79ce938127f88fe07e409c1817f477dbe7ea"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3e851448078f5b01f6264915df3cfef75e323a12"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/910d7749346c4b0acdc6e4adfdc4a9984281a206"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/91f548e920fbf8be3f285bfa3fa045ae017e836d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bc1c9ce8aeff45318332035dbef9713fb9e982d7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c9c2a51f91aea70e89b496cac360cd795a2b3c26"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Deferred"}

{"bugzilla": {"description": "mm/hugetlb: fix folio is still mapped when deleted", "id": "2405113", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2405113"}, "csaw": false, "details": ["No description is available for this CVE."], "name": "CVE-2025-40006", "public_date": "2025-10-20T15:26:53Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-40006\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-40006\nhttps://git.kernel.org/stable/c/21ee79ce938127f88fe07e409c1817f477dbe7ea\nhttps://git.kernel.org/stable/c/3e851448078f5b01f6264915df3cfef75e323a12\nhttps://git.kernel.org/stable/c/7b7387650dcf2881fd8bb55bcf3c8bd6c9542dd7\nhttps://git.kernel.org/stable/c/910d7749346c4b0acdc6e4adfdc4a9984281a206\nhttps://git.kernel.org/stable/c/91f548e920fbf8be3f285bfa3fa045ae017e836d\nhttps://git.kernel.org/stable/c/bc1c9ce8aeff45318332035dbef9713fb9e982d7\nhttps://git.kernel.org/stable/c/c1dc0524ab2cc3982d4e0d2bfac71a0cd4d65c39\nhttps://git.kernel.org/stable/c/c9c2a51f91aea70e89b496cac360cd795a2b3c26"]}

{"created": "2025-10-21T09:39:45.543742+00:00", "updated": "2025-10-21T09:39:45.543768+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}