{"cve":"CVE-2026-97556","nvd":{"published":"2026-09-25T11:17:06.077","modified":"2026-10-19T10:17:24.623","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: avoid leaking refcount when cifs_sb_tlink() fails\n\ncifs_oplock_break() takes over the reference that\ncifs_queue_oplock_break() acquired when it queued the work, and drops it\nwith _cifsFileInfo_put() once the break has been processed.\n\nOnly in setups with \"-o multiuser\", cifs_sb_tlink() may fail, at which\npoint cifs_oplock_break() returns without putting the file reference,\nmirroring the reference leak we already fixed in the companion patch to\ncifs_queue_oplock_break().\n\nThis would trigger a crash due to busy inodes on the next unmount:\n\n  BUG: Dentry ... still in use (1) [unmount of cifs cifs]\n  VFS: Busy inodes after unmount of cifs (cifs)\n\nDrop the reference on that path as well. Doing so before the out label\nmirrors the normal path, which also puts the reference before\ncifs_done_oplock_break().\n\nFound by Sashiko code review. The failure path was not exercised at\nruntime.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/1d1b0f1d812a4011a57bc6c70492c34a2e46c6dd","https://git.kernel.org/stable/c/23b26f4408ac3f35a482d2e5cf6fc865d4201b71","https://git.kernel.org/stable/c/55c5f095d4df14271b238f826e1392fda7b6e60e","https://git.kernel.org/stable/c/9ec991e148368e3207e98134c509a625097f7693","https://git.kernel.org/stable/c/dd03fd658ea59821505e0e643b6b7cbdf51c4e1d"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-97556","score":0.00206,"percentile":0.10495,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}