{"id":"CVE-2025-68226","state":"PUBLISHED","title":"smb: client: fix incomplete backport in cfids_invalidation_worker()","description":"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().","publishedAt":"2025-12-16T13:57:19.268Z","updatedAt":"2026-10-15T22:02:48.233Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bdb596ceb4b7c3f28786a33840263728217fbcf5","status":"affected","lessThan":"abd29b6e17a918fdd68352ce4813e167acc8727e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cached_dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"6.17.8","status":"affected","lessThan":"6.17.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cached_dir.c"]}],"references":["https://git.kernel.org/stable/c/abd29b6e17a918fdd68352ce4813e167acc8727e"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:56.034Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/68xxx/CVE-2025-68226.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-68226","state":"PUBLISHED","datePublished":"2025-12-16T13:57:19.268Z","dateUpdated":"2026-10-15T22:02:48.233Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-16T13:41:40.257Z"},"containers":{"cna":{"title":"smb: client: fix incomplete backport in cfids_invalidation_worker()","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()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bdb596ceb4b7c3f28786a33840263728217fbcf5","status":"affected","lessThan":"abd29b6e17a918fdd68352ce4813e167acc8727e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cached_dir.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"6.17.8","status":"affected","lessThan":"6.17.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/smb/client/cached_dir.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/abd29b6e17a918fdd68352ce4813e167acc8727e"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:10:18.178Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-68226","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T22:00:27.130563Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T22:02:48.233Z"}}]}}}