{"cve":"CVE-2026-89569","nvd":{"published":"2026-09-11T20:19:40.920","modified":"2026-10-19T09:17:52.730","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: serialize security confirmation handling\n\nrfcomm_security_cfm() looks up a session on session_list and then walks\nits DLC list without holding rfcomm_mutex. Since RFCOMM session teardown\nuses rfcomm_mutex, krfcommd can close and free the same session and DLCs\nconcurrently:\n\n  hci_rx_work                    krfcommd\n  -----------                    ---------\n  rfcomm_session_get()\n                                 rfcomm_lock()\n                                 rfcomm_session_close()\n                                   rfcomm_dlc_unlink()\n                                   rfcomm_session_del()\n                                     kfree(s)\n                                 rfcomm_unlock()\n  walk s->dlcs\n\nThe callback can then read a freed session list head and touch freed DLCs\nwhile updating their flags or timers.\n\nSerialize the session lookup and DLC traversal in rfcomm_security_cfm()\nwith rfcomm_mutex. This matches the existing RFCOMM session lifetime\nrules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()\nfrom tearing the objects down while the callback is using them.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440\n  Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89\n  Workqueue: hci0 hci_rx_work\n  Call Trace:\n   rfcomm_security_cfm+0x41c/0x440\n   hci_encrypt_cfm+0x139/0x590\n   hci_encrypt_change_evt+0x37b/0xc40\n   hci_event_packet+0x71b/0xb20\n   hci_rx_work+0x293/0x730\n  Allocated by task 69:\n   rfcomm_session_add+0x9e/0x2f0\n   rfcomm_run+0x44b/0x41e0\n  Freed by task 69:\n   kfree+0x131/0x3c0\n   rfcomm_session_del+0x188/0x220\n   rfcomm_run+0x1985/0x41e0","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":[],"references":["https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940","https://git.kernel.org/stable/c/3873f3449701b3dc98cba577923be6493598e7a1","https://git.kernel.org/stable/c/62ce8b33eb238cf18c15207332fbdc26d858f592","https://git.kernel.org/stable/c/759c185d0bbdb131357408f50b8735e04ed3caff","https://git.kernel.org/stable/c/7ded3264106418c6456ccceaafd9fda596ce12c3"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-89569","score":0.00344,"percentile":0.27683,"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."]}