{"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"}}}}