{"cve":"CVE-2025-68319","nvd":{"published":"2025-12-16T16:16:11.483","modified":"2026-10-21T13:18:22.140","status":"Deferred","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetconsole: Acquire su_mutex before navigating configs hierarchy\n\nThere is a race between operations that iterate over the userdata\ncg_children list and concurrent add/remove of userdata items through\nconfigfs. The update_userdata() function iterates over the\nnt->userdata_group.cg_children list, and count_extradata_entries() also\niterates over this same list to count nodes.\n\nQuoting from Documentation/filesystems/configfs.rst:\n> A subsystem can navigate the cg_children list and the ci_parent pointer\n> to see the tree created by the subsystem.  This can race with configfs'\n> management of the hierarchy, so configfs uses the subsystem mutex to\n> protect modifications.  Whenever a subsystem wants to navigate the\n> hierarchy, it must do so under the protection of the subsystem\n> mutex.\n\nWithout proper locking, if a userdata item is added or removed\nconcurrently while these functions are iterating, the list can be\naccessed in an inconsistent state. For example, the list_for_each() loop\ncan reach a node that is being removed from the list by list_del_init()\nwhich sets the nodes' .next pointer to point to itself, so the loop will\nnever end (or reach the WARN_ON_ONCE in update_userdata() ).\n\nFix this by holding the configfs subsystem mutex (su_mutex) during all\noperations that iterate over cg_children.\nThis includes:\n- userdatum_value_store() which calls update_userdata() to iterate over\n  cg_children\n- All sysdata_*_enabled_store() functions which call\n  count_extradata_entries() to iterate over cg_children\n\nThe su_mutex must be acquired before dynamic_netconsole_mutex to avoid\npotential lock ordering issues, as configfs operations may already hold\nsu_mutex when calling into our code.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/932c0c7a7ec413399febca5fe3dddf913bb5c924","https://git.kernel.org/stable/c/d7d2fcf7ae31471b4e08b7e448b8fd0ec2e06a1b","https://git.kernel.org/stable/c/ff70aa7e8cf05745fdba7258952a8bedf33ea336"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2025-68319","score":0.00215,"percentile":0.11753,"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."]}