{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-68226", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-16T13:41:40.257Z", "datePublished": "2025-12-16T13:57:19.268Z", "dateUpdated": "2026-08-05T12:10:18.178Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:10:18.178Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix incomplete backport in cfids_invalidation_worker()\n\nThe previous commit bdb596ceb4b7 (\"smb: client: fix potential UAF in\nsmb2_close_cached_fid()\") was an incomplete backport and missed one\nkref_put() call in cfids_invalidation_worker() that should have been\nconverted to close_cached_dir()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerable SMB client path is driven by a remote SMB peer: a malicious server can grant a cached directory lease and then force a session loss and reconnect that reaches the invalidation worker. This requires only network access to the established client connection.\nAC:L - The server controls the lease grant, connection failure or session-expired response, and reconnect timing, while the worker commonly holds the final lease reference. Triggering the lock and preemption imbalance therefore requires no uncontrollable race.\nPR:N - The remote SMB peer needs no privileges on the client and can accept guest or supplied credentials. Although mounting CIFS normally requires victim-side CAP_SYS_ADMIN, that is a deployment and user-interaction prerequisite rather than an attacker privilege.\nUI:R - A victim or administrator must mount or otherwise connect to the SMB share, which can create the cached root-directory handle. The remote peer can subsequently trigger the flaw without further interaction.\nS:U - The vulnerable cached-directory worker and resulting impacts reside within the same Linux kernel security authority. This does not inherently cross a VM, IOMMU, or other security boundary.\nC:H - The unpaired spin unlock can release cfid_list_lock while another CPU owns it, allowing concurrent cached-fid list and lifetime operations to cause use-after-free or heap corruption. Conservatively, that corruption can expose arbitrary kernel memory.\nI:H - Breaking cfid_list_lock serialization permits concurrent list-pointer and object-lifetime writes, potentially producing exploitable kernel heap corruption and control-flow modification. This supports arbitrary modification or kernel code execution.\nA:H - The flaw underflows the worker's preemption state when the final reference is dropped, producing workqueue atomic-state and scheduling failures. It can panic, hang, or otherwise destabilize the kernel and is repeatable by the remote SMB peer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cached_dir.c" ], "versions": [ { "version": "bdb596ceb4b7c3f28786a33840263728217fbcf5", "lessThan": "abd29b6e17a918fdd68352ce4813e167acc8727e", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cached_dir.c" ], "versions": [ { "version": "6.17.8", "lessThan": "6.17.10", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17.8", "versionEndExcluding": "6.17.10" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/abd29b6e17a918fdd68352ce4813e167acc8727e" } ], "title": "smb: client: fix incomplete backport in cfids_invalidation_worker()", "x_generator": { "engine": "bippy-1.2.0" } } } }