{"id":"AZL-100721","summary":"CVE-2026-89569 affecting package kernel 6.6.150.1-1","details":"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-\u003edlcs\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","modified":"2026-09-12T14:15:31.089509796Z","published":"2026-09-11T20:19:40Z","upstream":["CVE-2026-89569"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89569"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100721.json"}}],"schema_version":"1.9.0"}