CVE-2025-68809
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: vfs: fix race on m_flags in vfs_cache ksmbd maintains delete-on-close and pending-delete state in ksmbd_inode->m_flags. In vfs_cache.c this field is accessed under inconsistent locking: some paths read and modify m_flags under ci->m_lock while others do so without taking the lock at all. Examples: - ksmbd_query_inode_status() and __ksmbd_inode_close() use ci->m_lock when checking or updating m_flags. - ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(), ksmbd_clear_inode_pending_delete() and ksmbd_fd_set_delete_on_close() used to read and modify m_flags without ci->m_lock. This creates a potential data race on m_flags when multiple threads open, close and delete the same file concurrently. In the worst case delete-on-close and pending-delete bits can be lost or observed in an inconsistent state, leading to confusing delete semantics (files that stay on disk after delete-on-close, or files that disappear while still in use). Fix it by: - Making ksmbd_query_inode_status() look at m_flags under ci->m_lock after dropping inode_hash_lock. - Adding ci->m_lock protection to all helpers that read or modify m_flags (ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(), ksmbd_clear_inode_pending_delete(), ksmbd_fd_set_delete_on_close()). - Keeping the existing ci->m_lock protection in __ksmbd_inode_close(), and moving the actual unlink/xattr removal outside the lock. This unifies the locking around m_flags and removes the data race while preserving the existing delete-on-close behaviour.
Severity
CRITICAL
CVSS score
9.1
(v3.1)
Vulnerability status
Deferred
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-01-13 16:16:03.080000
Last modified
2026-10-30 13:18:24.440000
View original CVE JSON
{
"id": "CVE-2025-68809",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-01-13T16:16:03.080",
"lastModified": "2026-10-30T13:18:24.440",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: vfs: fix race on m_flags in vfs_cache\n\nksmbd maintains delete-on-close and pending-delete state in\nksmbd_inode->m_flags. In vfs_cache.c this field is accessed under\ninconsistent locking: some paths read and modify m_flags under\nci->m_lock while others do so without taking the lock at all.\n\nExamples:\n\n - ksmbd_query_inode_status() and __ksmbd_inode_close() use\n ci->m_lock when checking or updating m_flags.\n - ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),\n ksmbd_clear_inode_pending_delete() and ksmbd_fd_set_delete_on_close()\n used to read and modify m_flags without ci->m_lock.\n\nThis creates a potential data race on m_flags when multiple threads\nopen, close and delete the same file concurrently. In the worst case\ndelete-on-close and pending-delete bits can be lost or observed in an\ninconsistent state, leading to confusing delete semantics (files that\nstay on disk after delete-on-close, or files that disappear while still\nin use).\n\nFix it by:\n\n - Making ksmbd_query_inode_status() look at m_flags under ci->m_lock\n after dropping inode_hash_lock.\n - Adding ci->m_lock protection to all helpers that read or modify\n m_flags (ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(),\n ksmbd_clear_inode_pending_delete(), ksmbd_fd_set_delete_on_close()).\n - Keeping the existing ci->m_lock protection in __ksmbd_inode_close(),\n and moving the actual unlink/xattr removal outside the lock.\n\nThis unifies the locking around m_flags and removes the data race while\npreserving the existing delete-on-close behaviour."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nksmbd: vfs: corregir condición de carrera en m_flags en vfs_cache\n\nksmbd mantiene el estado de eliminación al cerrar y eliminación pendiente en ksmbd_inode->m_flags. En vfs_cache.c, este campo es accedido bajo un bloqueo inconsistente: algunas rutas leen y modifican m_flags bajo ci->m_lock mientras que otras lo hacen sin tomar el bloqueo en absoluto.\n\nEjemplos:\n\n - ksmbd_query_inode_status() y __ksmbd_inode_close() usan ci->m_lock al verificar o actualizar m_flags.\n - ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(), ksmbd_clear_inode_pending_delete() y ksmbd_fd_set_delete_on_close() solían leer y modificar m_flags sin ci->m_lock.\n\nEsto crea una potencial condición de carrera de datos en m_flags cuando múltiples hilos abren, cierran y eliminan el mismo archivo concurrentemente. En el peor de los casos, los bits de eliminación al cerrar y eliminación pendiente pueden perderse u observarse en un estado inconsistente, lo que lleva a semánticas de eliminación confusas (archivos que permanecen en el disco después de la eliminación al cerrar, o archivos que desaparecen mientras aún están en uso).\n\nSolucionarlo mediante:\n\n - Haciendo que ksmbd_query_inode_status() examine m_flags bajo ci->m_lock después de liberar inode_hash_lock.\n - Añadiendo protección ci->m_lock a todas las funciones auxiliares que leen o modifican m_flags (ksmbd_inode_pending_delete(), ksmbd_set_inode_pending_delete(), ksmbd_clear_inode_pending_delete(), ksmbd_fd_set_delete_on_close()).\n - Manteniendo la protección ci->m_lock existente en __ksmbd_inode_close(), y moviendo la eliminación real de unlink/xattr fuera del bloqueo.\n\nEsto unifica el bloqueo alrededor de m_flags y elimina la condición de carrera de datos mientras se preserva el comportamiento existente de eliminación al cerrar."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/smb/server/vfs_cache.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "f44158485826c076335d6860d35872271a83791d",
"lessThan": "a4fd1fdf505facfae26b5654c9eff321f4cbc1a7",
"versionType": "git",
"status": "affected"
},
{
"version": "f44158485826c076335d6860d35872271a83791d",
"lessThan": "5adad9727a815c26013b0d41cfee92ffa7d4037c",
"versionType": "git",
"status": "affected"
},
{
"version": "f44158485826c076335d6860d35872271a83791d",
"lessThan": "ccc78781041589ea383e61d5d7a1e9a31b210b93",
"versionType": "git",
"status": "affected"
},
{
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"versionType": "git",
"status": "affected"
},
{
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"lessThan": "991f8a79db99b14c48d20d2052c82d65b9186cad",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/smb/server/vfs_cache.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.15",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.15",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.120",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.64",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.3",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.19",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
"baseScore": 9.1,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 5.2
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/5adad9727a815c26013b0d41cfee92ffa7d4037c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/991f8a79db99b14c48d20d2052c82d65b9186cad",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/a4fd1fdf505facfae26b5654c9eff321f4cbc1a7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/ccc78781041589ea383e61d5d7a1e9a31b210b93",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/ee63729760f5b61a66f345c54dc4c7514e62383d",
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}
]
}