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CVE-2025-40318 (GCVE-0-2025-40318)

Vulnerability from cvelistv5 – Published: 2025-12-08 00:46 – Updated: 2026-08-05 12:09
VLAI
Title
Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once hci_cmd_sync_dequeue_once() does lookup and then cancel the entry under two separate lock sections. Meanwhile, hci_cmd_sync_work() can also delete the same entry, leading to double list_del() and "UAF". Fix this by holding cmd_sync_work_lock across both lookup and cancel, so that the entry cannot be removed concurrently.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: f00f36db76eb8fd10d13e80e2590f23b5beaa54d , < 0a94f7e017438935c09ef833a1aa908ad9875213 (git)
Affected: 1499f79995c7ee58e3bfeeff75f6d1b37dcda881 , < 932c0a4f77ac13e526fdd5b42914d29c9821d389 (git)
Affected: 505ea2b295929e7be2b4e1bc86ee31cb7862fb01 , < ae76cf6c2c842944c6514c57df54d728f1916553 (git)
Affected: 505ea2b295929e7be2b4e1bc86ee31cb7862fb01 , < 9cd536970192b72257afcdfba0bfc09993e6f19c (git)
Affected: 505ea2b295929e7be2b4e1bc86ee31cb7862fb01 , < 09b0cd1297b4dbfe736aeaa0ceeab2265f47f772 (git)
Affected: 357603f4d396d85fbf0045512efaf1d7f7394ed7 (git)
Affected: 6.1.120 , < 6.1.159 (semver)
Affected: 6.6.51 , < 6.6.117 (semver)
Affected: 6.8.9 , < 6.9 (semver)
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Linux Linux Affected: 6.9
Unaffected: 0 , < 6.9 (semver)
Unaffected: 6.1.159 , ≤ 6.1.* (semver)
Unaffected: 6.6.117 , ≤ 6.6.* (semver)
Unaffected: 6.12.58 , ≤ 6.12.* (semver)
Unaffected: 6.17.8 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "6.9"
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              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
              "version": "6.1.159",
              "versionType": "semver"
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            {
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              "status": "unaffected",
              "version": "6.6.117",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.58",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
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          "nodes": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.159",
                  "versionStartIncluding": "6.1.120",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once\n\nhci_cmd_sync_dequeue_once() does lookup and then cancel\nthe entry under two separate lock sections. Meanwhile,\nhci_cmd_sync_work() can also delete the same entry,\nleading to double list_del() and \"UAF\".\n\nFix this by holding cmd_sync_work_lock across both\nlookup and cancel, so that the entry cannot be removed\nconcurrently."
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
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              "lang": "en",
              "value": "AV:A - The flaw is in the Bluetooth HCI command-sync queue, and the create-connection entries it manages are queued and aborted in response to LE/ACL link events from a peer in radio range (advertising reports driving `check_pending_le_conn()`, and `le_conn_timeout` when the peer stops responding). An attacker within Bluetooth range can drive both the queue and cancel sides without any local access.\nAC:L - The attacker controls both sides of the race \u2014 repeatedly forcing connection attempts and aborts cycles `hci_cancel_connect_sync()` against the `cmd_sync_work` kthread draining the same list entry, and the attempt can be retried without limit. The window sits between two lock acquisitions in the same function with the worker on a separate CPU, making it readily hit on SMP.\nPR:N - The adjacent attacker holds no credentials on the target: the LE create-connection queue/cancel cycle happens entirely before pairing or authentication completes. Even on the purely local path only an unprivileged AF_BLUETOOTH socket is needed, since `l2cap_sock_create()` gates only SOCK_RAW behind CAP_NET_RAW.\nUI:N - Background LE auto-connect and connection-timeout handling proceed autonomously in kernel workqueues with no victim action. No file must be opened, device mounted, or prompt accepted.\nS:U - The corruption is confined to kernel heap objects managed by the same kernel security authority; there is no VM, IOMMU, or sandbox boundary crossed. Impact is standard in-kernel compromise.\nC:H - The use-after-free reads `entry-\u003edestroy` and `entry-\u003edata` out of a freed kmalloc-64 object and dereferences them, and the resulting hijacked call plus double-`list_del` write primitive can be leveraged into arbitrary kernel memory disclosure. Freed-slab reads alone already expose adjacent kernel heap contents.\nI:H - `_hci_cmd_sync_cancel_entry()` calls a function pointer read from freed memory and then performs a double `list_del()` that writes attacker-groomable pointers to attacker-groomable addresses, plus a double `kfree()`. That combination is a direct control-flow-hijack and arbitrary-write path to full kernel code execution.\nA:H - Without successful grooming the same code path dereferences LIST_POISON or freed slab contents, producing a `list_del corruption` BUG, GPF, or panic. The double free additionally corrupts the slab allocator, crashing the system."
            }
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/0a94f7e017438935c09ef833a1aa908ad9875213"
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          "url": "https://git.kernel.org/stable/c/932c0a4f77ac13e526fdd5b42914d29c9821d389"
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        {
          "url": "https://git.kernel.org/stable/c/09b0cd1297b4dbfe736aeaa0ceeab2265f47f772"
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      "title": "Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once",
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    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40318",
    "datePublished": "2025-12-08T00:46:45.382Z",
    "dateReserved": "2025-04-16T07:20:57.186Z",
    "dateUpdated": "2026-08-05T12:09:29.032Z",
    "state": "PUBLISHED"
  },
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  "dataVersion": "5.2",
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      "date": "2026-09-16",
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-30T08:37:33+00:00",
      "cve": "CVE-2025-40318",
      "id": "CVE-2025-40318",
      "initial_release_date": "2025-12-08T00:00:00+00:00",
      "product_status:fixed": "1224",
      "product_status:known_affected": "22",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: hci_sync: fix race in hci_cmd_sync_dequeue_once",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40318.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-11T01:53:51Z",
      "cve": "CVE-2025-40318",
      "id": "CVE-2025-40318",
      "initial_release_date": "2025-12-09T00:24:12Z",
      "product_status:first_fixed": "2",
      "product_status:known_affected": "394",
      "product_status:known_not_affected": "429",
      "product_status:recommended": "467",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-40318",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-40318.json",
      "version": "33"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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