{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.100-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.5-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  Bluetooth: 6lowpan: hold L2CAP conn across debugfs control  get_l2cap_conn() looks up an LE hci_conn under hdev protection, but then drops that protection before reading hcon-\u003el2cap_data and before lowpan_control_write() later dereferences conn-\u003ehcon.  A disconnect or device close can tear down the same L2CAP connection in that window.  The buggy scenario involves two paths, with each column showing the order within that path:  6LoWPAN control write:              HCI disconnect/device close:   1. get_l2cap_conn() finds hcon      1. hci_disconn_cfm() dispatches      and hcon-\u003el2cap_data.               the L2CAP disconnect callback.   2. get_l2cap_conn() drops hdev      2. l2cap_conn_del() clears      protection and returns conn.        hcon-\u003el2cap_data and drops the                                          L2CAP connection reference.   3. lowpan_control_write() reads     3. hci_conn_del() removes and drops      conn-\u003ehcon.                         the HCI connection.  Take a reference to the L2CAP connection with l2cap_conn_hold_unless_zero() while hdev is still locked, and drop that reference after the debugfs command's last use of conn.  This mirrors the existing L2CAP ACL receive-side handoff and keeps the connection dereferenceable after leaving hdev protection.  Export the existing helper so the bluetooth_6lowpan module can use the same lifetime primitive.  Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in lowpan_control_write+0x374/0x520 The buggy address belongs to the object at ffff888111b9d000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes inside of freed 1024-byte region [ffff888111b9d000, ffff888111b9d400) Read of size 8 Call trace:   dump_stack_lvl+0x66/0xa0   print_report+0xce/0x5f0   lowpan_control_write+0x374/0x520 (net/bluetooth/6lowpan.c:1131)   srso_alias_return_thunk+0x5/0xfbef5   __virt_addr_valid+0x19f/0x330   kasan_report+0xe0/0x110   __debugfs_file_get+0xf7/0x400   full_proxy_write+0x9e/0xd0   vfs_write+0x1b0/0x810   ksys_write+0xd2/0x170   dnotify_flush+0x32/0x220   do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)   entry_SYSCALL_64_after_hwframe+0x77/0x7f Allocated by task stack:   kasan_save_stack+0x33/0x60   kasan_save_track+0x17/0x60   __kasan_kmalloc+0xaa/0xb0   l2cap_conn_add+0x45/0x520   l2cap_chan_connect+0xac6/0xd90   l2cap_sock_connect+0x216/0x350   __sys_connect+0x101/0x130   __x64_sys_connect+0x40/0x50   do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)   entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task stack:   kasan_save_stack+0x33/0x60   kasan_save_track+0x17/0x60   kasan_save_free_info+0x3b/0x60   __kasan_slab_free+0x5f/0x80   kfree+0x313/0x590   hci_conn_hash_flush+0xc0/0x140   hci_dev_close_sync+0x41a/0xb00   hci_dev_close+0x12f/0x160   hci_sock_ioctl+0x157/0x570   sock_do_ioctl+0xf7/0x210   sock_ioctl+0x32f/0x490   __x64_sys_ioctl+0xc7/0x110   do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)   entry_SYSCALL_64_after_hwframe+0x77/0x7f   kasan_record_aux_stack+0xa7/0xc0   insert_work+0x32/0x100   __queue_work+0x262/0xa60   queue_work_on+0xad/0xb0   l2cap_connect_cfm+0x4ef/0x670   hci_le_remote_feat_complete_evt+0x247/0x430   hci_event_packet+0x360/0x6f0   hci_rx_work+0x2ae/0x7a0   process_one_work+0x4fd/0xbc0   worker_thread+0x2d8/0x570   kthread+0x1ad/0x1f0   ret_from_fork+0x3c9/0x540   ret_from_fork_asm+0x1a/0x30",
  "id": "DEBIAN-CVE-2026-72336",
  "modified": "2026-09-14T16:47:29.494682517Z",
  "published": "2026-08-15T06:22:06.817Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-72336"
    }
  ],
  "upstream": [
    "CVE-2026-72336"
  ]
}