{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68809", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T10:30:51.047Z", "datePublished": "2026-01-13T15:29:15.817Z", "dateUpdated": "2026-08-05T12:11:40.534Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:11:40.534Z" }, "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." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:N - The race is reachable through ksmbd SMB2 requests received over TCP, normally port 445, including CREATE, SET_INFO, QUERY_INFO, and CLOSE operations.\nAC:L - An attacker can control both sides by opening multiple handles to the same inode and issuing concurrent requests or disconnects that ksmbd processes on separate workers.\nPR:N - Although a valid session, writable tree connection, and delete-capable handle are normally required, ksmbd supports unauthenticated guest sessions and guest-writable shares. Such deployments let a remote attacker reach the race without possessing credentials.\nUI:N - The attacker can create the necessary handles, race the requests, and trigger final close without any victim action.\nS:U - The affected SMB server, filesystem operations, and resulting data impact remain within the host kernel's security authority.\nC:N - The raced field is an aligned unsigned flag word, and the affected operations neither expose data nor corrupt pointers, object lifetimes, or adjacent memory.\nI:H - Lost or stale pending-delete and delete-on-close bits can cause attacker-selected files, directories, or alternate data streams to be unlinked despite the intended state, producing persistent data loss in a critical writable share.\nA:H - Unexpected and repeatable deletion of operational files while they are in use can persistently make shared storage or dependent services unavailable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/vfs_cache.c" ], "versions": [ { "version": "f44158485826c076335d6860d35872271a83791d", "lessThan": "5adad9727a815c26013b0d41cfee92ffa7d4037c", "status": "affected", "versionType": "git" }, { "version": "f44158485826c076335d6860d35872271a83791d", "lessThan": "ccc78781041589ea383e61d5d7a1e9a31b210b93", "status": "affected", "versionType": "git" }, { "version": "f44158485826c076335d6860d35872271a83791d", "lessThan": "ee63729760f5b61a66f345c54dc4c7514e62383d", "status": "affected", "versionType": "git" }, { "version": "f44158485826c076335d6860d35872271a83791d", "lessThan": "991f8a79db99b14c48d20d2052c82d65b9186cad", "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/smb/server/vfs_cache.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.120", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.64", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.3", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "5.15", "versionEndExcluding": "6.6.120" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5adad9727a815c26013b0d41cfee92ffa7d4037c" }, { "url": "https://git.kernel.org/stable/c/ccc78781041589ea383e61d5d7a1e9a31b210b93" }, { "url": "https://git.kernel.org/stable/c/ee63729760f5b61a66f345c54dc4c7514e62383d" }, { "url": "https://git.kernel.org/stable/c/991f8a79db99b14c48d20d2052c82d65b9186cad" } ], "title": "ksmbd: vfs: fix race on m_flags in vfs_cache", "x_generator": { "engine": "bippy-1.2.0" } } } }