{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/sco.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "391f83547b7b2c63e4b572ab838e10a06cfa4425",
              "status": "affected",
              "version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
              "versionType": "git"
            },
            {
              "lessThan": "ecb9a843be4d6fd710d7026e359f21015a062572",
              "status": "affected",
              "version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/sco.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17.8",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SCO: Fix UAF on sco_conn_free\n\nBUG: KASAN: slab-use-after-free in sco_conn_free net/bluetooth/sco.c:87 [inline]\nBUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:65 [inline]\nBUG: KASAN: slab-use-after-free in sco_conn_put+0xdd/0x410\nnet/bluetooth/sco.c:107\nWrite of size 8 at addr ffff88811cb96b50 by task kworker/u17:4/352\n\nCPU: 1 UID: 0 PID: 352 Comm: kworker/u17:4 Not tainted\n6.17.0-rc5-g717368f83676 #4 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nWorkqueue: hci13 hci_cmd_sync_work\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0x10b/0x170 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0x191/0x550 mm/kasan/report.c:482\n kasan_report+0xc4/0x100 mm/kasan/report.c:595\n sco_conn_free net/bluetooth/sco.c:87 [inline]\n kref_put include/linux/kref.h:65 [inline]\n sco_conn_put+0xdd/0x410 net/bluetooth/sco.c:107\n sco_connect_cfm+0xb4/0xae0 net/bluetooth/sco.c:1441\n hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]\n hci_conn_failed+0x20a/0x2e0 net/bluetooth/hci_conn.c:1313\n hci_conn_unlink+0x55f/0x810 net/bluetooth/hci_conn.c:1121\n hci_conn_del+0xb6/0x1110 net/bluetooth/hci_conn.c:1147\n hci_abort_conn_sync+0x8c5/0xbb0 net/bluetooth/hci_sync.c:5689\n hci_cmd_sync_work+0x281/0x380 net/bluetooth/hci_sync.c:332\n process_one_work kernel/workqueue.c:3236 [inline]\n process_scheduled_works+0x77e/0x1040 kernel/workqueue.c:3319\n worker_thread+0xbee/0x1200 kernel/workqueue.c:3400\n kthread+0x3c7/0x870 kernel/kthread.c:463\n ret_from_fork+0x13a/0x1e0 arch/x86/kernel/process.c:148\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \u003c/TASK\u003e\n\nAllocated by task 31370:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x30/0x70 mm/kasan/common.c:68\n poison_kmalloc_redzone mm/kasan/common.c:388 [inline]\n __kasan_kmalloc+0x82/0x90 mm/kasan/common.c:405\n kasan_kmalloc include/linux/kasan.h:260 [inline]\n __do_kmalloc_node mm/slub.c:4382 [inline]\n __kmalloc_noprof+0x22f/0x390 mm/slub.c:4394\n kmalloc_noprof include/linux/slab.h:909 [inline]\n sk_prot_alloc+0xae/0x220 net/core/sock.c:2239\n sk_alloc+0x34/0x5a0 net/core/sock.c:2295\n bt_sock_alloc+0x3c/0x330 net/bluetooth/af_bluetooth.c:151\n sco_sock_alloc net/bluetooth/sco.c:562 [inline]\n sco_sock_create+0xc0/0x350 net/bluetooth/sco.c:593\n bt_sock_create+0x161/0x3b0 net/bluetooth/af_bluetooth.c:135\n __sock_create+0x3ad/0x780 net/socket.c:1589\n sock_create net/socket.c:1647 [inline]\n __sys_socket_create net/socket.c:1684 [inline]\n __sys_socket+0xd5/0x330 net/socket.c:1731\n __do_sys_socket net/socket.c:1745 [inline]\n __se_sys_socket net/socket.c:1743 [inline]\n __x64_sys_socket+0x7a/0x90 net/socket.c:1743\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xc7/0x240 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFreed by task 31374:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x30/0x70 mm/kasan/common.c:68\n kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576\n poison_slab_object mm/kasan/common.c:243 [inline]\n __kasan_slab_free+0x3d/0x50 mm/kasan/common.c:275\n kasan_slab_free include/linux/kasan.h:233 [inline]\n slab_free_hook mm/slub.c:2428 [inline]\n slab_free mm/slub.c:4701 [inline]\n kfree+0x199/0x3b0 mm/slub.c:4900\n sk_prot_free net/core/sock.c:2278 [inline]\n __sk_destruct+0x4aa/0x630 net/core/sock.c:2373\n sco_sock_release+0x2ad/0x300 net/bluetooth/sco.c:1333\n __sock_release net/socket.c:649 [inline]\n sock_close+0xb8/0x230 net/socket.c:1439\n __fput+0x3d1/0x9e0 fs/file_table.c:468\n task_work_run+0x206/0x2a0 kernel/task_work.c:227\n get_signal+0x1201/0x1410 kernel/signal.c:2807\n arch_do_signal_or_restart+0x34/0x740 arch/x86/kernel/signal.c:337\n exit_to_user_mode_loop+0x68/0xc0 kernel/entry/common.c:40\n exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]\n s\n---truncated---"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - The vulnerable object is a Bluetooth SCO connection whose teardown half of the race (`hci_conn_failed`/`sco_connect_cfm`/`sco_disconn_cfm` on the hci_cmd_sync workqueue) is driven by link-layer events an in-range Bluetooth device controls, and the dangling `conn-\u003esk` is also consumed by the remote-fed `sco_recv_frame()` path. Per kernel guidance, Bluetooth-reachable bugs are Adjacent.\nAC:L - The attacker controls both sides of the race \u2014 the unlocked `sk_state` check in `sco_sock_connect()` lets concurrent connect()/close() calls on one socket deterministically leave a stale `conn-\u003esk`, and connection aborts can be forced at will by connecting to an unresponsive bdaddr or by a nearby device dropping the (e)SCO link. The sequence can be looped indefinitely until it wins.\nPR:L - No capability check exists in `bt_sock_create()`, `sco_sock_create()`, `sco_sock_bind()` or `sco_sock_connect()`, so any unprivileged local process can create, connect and close SCO sockets to drive the socket-lifecycle side of the race. Only basic user-level access is required.\nUI:N - Exploitation needs only socket syscalls plus Bluetooth link events; no victim action such as pairing confirmation, mounting or opening a file is required.\nS:U - The use-after-free corrupts kernel slab memory within the same kernel security authority; no VM, IOMMU or sandbox boundary is crossed.\nC:H - The dangling `conn-\u003esk` is dereferenced in `sco_conn_ready()`, `sco_recv_frame()` and `sco_sock_hold()`, letting an attacker who reclaims the freed sock slot read and exfiltrate reclaimed kernel data (e.g. via `sock_queue_rcv_skb()` into a groomed object), giving arbitrary kernel-memory disclosure potential.\nI:H - `sco_conn_free()` performs an 8-byte write at a fixed offset into the freed allocation, and `sco_conn_ready()` makes an indirect call through `sk-\u003esk_state_change` on the freed sock \u2014 together a write primitive plus control-flow hijack enabling privilege escalation.\nA:H - Even unexploited, the slab-use-after-free corrupts kernel memory and reliably produces a KASAN splat/oops or panic, and the corrupted refcounts and pointers can hang or crash the Bluetooth stack and the system."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:09:26.901Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/391f83547b7b2c63e4b572ab838e10a06cfa4425"
        },
        {
          "url": "https://git.kernel.org/stable/c/ecb9a843be4d6fd710d7026e359f21015a062572"
        }
      ],
      "title": "Bluetooth: SCO: Fix UAF on sco_conn_free",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40309",
    "datePublished": "2025-12-08T00:46:34.785Z",
    "dateReserved": "2025-04-16T07:20:57.185Z",
    "dateUpdated": "2026-08-05T12:09:26.901Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}