{"cve":"CVE-2025-40320","nvd":{"published":"2025-12-08T01:16:04.670","modified":"2026-10-15T22:19:08.160","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix potential cfid UAF in smb2_query_info_compound\n\nWhen smb2_query_info_compound() retries, a previously allocated cfid may\nhave been freed in the first attempt.\nBecause cfid wasn't reset on replay, later cleanup could act on a stale\npointer, leading to a potential use-after-free.\n\nReinitialize cfid to NULL under the replay label.\n\nExample trace (trimmed):\n\nrefcount_t: underflow; use-after-free.\nWARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcount_warn_saturate+0x9c/0x110\n[...]\nRIP: 0010:refcount_warn_saturate+0x9c/0x110\n[...]\nCall Trace:\n <TASK>\n smb2_query_info_compound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]\n ? step_into+0x10d/0x690\n ? __legitimize_path+0x28/0x60\n smb2_queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]\n smb311_queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f]\n ? kmem_cache_alloc+0x18a/0x340\n ? getname_flags+0x46/0x1e0\n cifs_statfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f]\n statfs_by_dentry+0x67/0x90\n vfs_statfs+0x16/0xd0\n user_statfs+0x54/0xa0\n __do_sys_statfs+0x20/0x50\n do_syscall_64+0x58/0x80","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":[],"references":["https://git.kernel.org/stable/c/327f89c21601ebb7889f8c97754b76f08ce95a0c","https://git.kernel.org/stable/c/5c76f9961c170552c1d07c830b5e145475151600","https://git.kernel.org/stable/c/939c4e33005e2a56ea8fcedddf0da92df864bd3b","https://git.kernel.org/stable/c/b556c278d43f4707a9073ca74d55581b4f279806"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:16:40.427100871+00:00"},"epss":{"cve":"CVE-2025-40320","score":0.00418,"percentile":0.35832,"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."]}