{"id":21491,"date":"2026-09-12T04:31:15","date_gmt":"2026-09-11T20:31:15","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-89569"},"modified":"2026-09-12T04:31:15","modified_gmt":"2026-09-11T20:31:15","slug":"cve-2026-89569","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-89569","title":{"rendered":"CVE-2026-89569 &#8211; In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: se"},"content":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>Bluetooth: RFCOMM: serialize security confirmation handling<\/p>\n<p>rfcomm_security_cfm() looks up a session on session_list and then walks<br \/>\nits DLC list without holding rfcomm_mutex. Since RFCOMM session teardown<br \/>\nuses rfcomm_mutex, krfcommd can close and free the same session and DLCs<br \/>\nconcurrently:<\/p>\n<p>  hci_rx_work                    krfcommd<br \/>\n  &#8212;&#8212;&#8212;&#8211;                    &#8212;&#8212;&#8212;<br \/>\n  rfcomm_session_get()<br \/>\n                                 rfcomm_lock()<br \/>\n                                 rfcomm_session_close()<br \/>\n                                   rfcomm_dlc_unlink()<br \/>\n                                   rfcomm_session_del()<br \/>\n                                     kfree(s)<br \/>\n                                 rfcomm_unlock()<br \/>\n  walk s-&gt;dlcs<\/p>\n<p>The callback can then read a freed session list head and touch freed DLCs<br \/>\nwhile updating their flags or timers.<\/p>\n<p>Serialize the session lookup and DLC traversal in rfcomm_security_cfm()<br \/>\nwith rfcomm_mutex. This matches the existing RFCOMM session lifetime<br \/>\nrules and prevents concurrent rfcomm_session_del() \/ rfcomm_dlc_unlink()<br \/>\nfrom tearing the objects down while the callback is using them.<\/p>\n<p>KASAN reported:<\/p>\n<p>  BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c\/0x440<br \/>\n  Read of size 8 at addr ffff888111fb3960 by task kworker\/u17:1\/89<br \/>\n  Workqueue: hci0 hci_rx_work<br \/>\n  Call Trace:<br \/>\n   rfcomm_security_cfm+0x41c\/0x440<br \/>\n   hci_encrypt_cfm+0x139\/0x590<br \/>\n   hci_encrypt_change_evt+0x37b\/0xc40<br \/>\n   hci_event_packet+0x71b\/0xb20<br \/>\n   hci_rx_work+0x293\/0x730<br \/>\n  Allocated by task 69:<br \/>\n   rfcomm_session_add+0x9e\/0x2f0<br \/>\n   rfcomm_run+0x44b\/0x41e0<br \/>\n  Freed by task 69:<br \/>\n   kfree+0x131\/0x3c0<br \/>\n   rfcomm_session_del+0x188\/0x220<br \/>\n   rfcomm_run+0x1985\/0x41e0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>Bluetooth: RFCOMM: serialize security confirmation handling<\/p>\n<p>rfcomm_security_cfm() looks up a session on session_list and then walk<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21491","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21491","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21491"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21491"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21491"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}