Vulnerability-Lookup

FKIE_CVE-2026-90093

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-18 18:17

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: access chan->conn safely in get/setsockopt Since commit b66774b48dd9 ("Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref") l2cap_chan::conn has held reference and remains non-NULL also after the corresponding hci_conn is deleted. In this state accessing various fields eg. hci_conn::hdev is invalid, which leads to KASAN crash in l2cap_sock_setsockopt() access of conn->hcon->hdev. Check l2cap_chan::conn.hcon corresponds to an alive hci_conn before trying to use it in l2cap_sock.c. Hold l2cap_chan_lock() in getsockopt/setsockopt to ensure it stays alive, and to avoid data races in l2cap_chan fields.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f49321c85785178214fd67f2e9b4b73d6363783b",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "lessThan": "ca2c4c26498643f421d35ffe258fafbd3ed461c3",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8f90405a4a6f1f1880dc07996b47bf57c712bd8a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8922c7940bae9ce4b1736dddb6362370793835c2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "91047a4396a8b1857a6f712a90cf33ec0012b189",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0b0e2bf39cf99e458d991b9df253727e036a7d7d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d3b739db5dc6f688a60d56da872fabaf65246032",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "50c38d9f42a529691e4e67ea9cedf4f0bfc8d277",
              "versionType": "git"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThan": "6.7",
              "status": "affected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThan": "6.13",
              "status": "affected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThan": "6.19",
              "status": "affected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2",
              "status": "affected",
              "version": "7.1.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: access chan-\u003econn safely in get/setsockopt\n\nSince commit b66774b48dd9 (\"Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref\")\nl2cap_chan::conn has held reference and remains non-NULL also after the\ncorresponding hci_conn is deleted.  In this state accessing various\nfields eg. hci_conn::hdev is invalid, which leads to KASAN crash in\nl2cap_sock_setsockopt() access of conn-\u003ehcon-\u003ehdev.\n\nCheck l2cap_chan::conn.hcon corresponds to an alive hci_conn before\ntrying to use it in l2cap_sock.c.  Hold l2cap_chan_lock() in\ngetsockopt/setsockopt to ensure it stays alive, and to avoid data races\nin l2cap_chan fields."
    }
  ],
  "id": "CVE-2026-90093",
  "lastModified": "2026-09-18T18:17:41.697",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-17T17:17:00.900",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-90093 (GCVE-0-2026-90093)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:06 – Updated: 2026-09-18 17:52

Title

Bluetooth: L2CAP: access chan->conn safely in get/setsockopt

Summary

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/f49321c8578517821…
https://git.kernel.org/stable/c/ca2c4c26498643f42…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b66774b48dd98f07254951f74ea6f513efe7ff8b , < f49321c85785178214fd67f2e9b4b73d6363783b (git) Affected: b66774b48dd98f07254951f74ea6f513efe7ff8b , < ca2c4c26498643f421d35ffe258fafbd3ed461c3 (git) Affected: 8f90405a4a6f1f1880dc07996b47bf57c712bd8a (git) Affected: 32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b (git) Affected: 8922c7940bae9ce4b1736dddb6362370793835c2 (git) Affected: 91047a4396a8b1857a6f712a90cf33ec0012b189 (git) Affected: 0b0e2bf39cf99e458d991b9df253727e036a7d7d (git) Affected: d3b739db5dc6f688a60d56da872fabaf65246032 (git) Affected: 50c38d9f42a529691e4e67ea9cedf4f0bfc8d277 (git) Affected: 5.10.265 , < 5.11 (semver) Affected: 5.15.216 , < 5.16 (semver) Affected: 6.1.183 , < 6.2 (semver) Affected: 6.6.145 , < 6.7 (semver) Affected: 6.12.97 , < 6.13 (semver) Affected: 6.18.39 , < 6.19 (semver) Affected: 7.1.4 , < 7.2 (semver)
Linux	Linux	Affected: 7.2 Unaffected: 0 , < 7.2 (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f49321c85785178214fd67f2e9b4b73d6363783b",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "lessThan": "ca2c4c26498643f421d35ffe258fafbd3ed461c3",
              "status": "affected",
              "version": "b66774b48dd98f07254951f74ea6f513efe7ff8b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8f90405a4a6f1f1880dc07996b47bf57c712bd8a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "32d783cafb46ff3ca58e6f9fd62c9c5f35eaf26b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8922c7940bae9ce4b1736dddb6362370793835c2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "91047a4396a8b1857a6f712a90cf33ec0012b189",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0b0e2bf39cf99e458d991b9df253727e036a7d7d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d3b739db5dc6f688a60d56da872fabaf65246032",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "50c38d9f42a529691e4e67ea9cedf4f0bfc8d277",
              "versionType": "git"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThan": "5.16",
              "status": "affected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThan": "6.7",
              "status": "affected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThan": "6.13",
              "status": "affected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThan": "6.19",
              "status": "affected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2",
              "status": "affected",
              "version": "7.1.4",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.10.265",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.216",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.1.183",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.6.145",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.12.97",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.18.39",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "7.1.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: access chan-\u003econn safely in get/setsockopt\n\nSince commit b66774b48dd9 (\"Bluetooth: L2CAP: Fix UAF in channel timeout by holding conn ref\")\nl2cap_chan::conn has held reference and remains non-NULL also after the\ncorresponding hci_conn is deleted.  In this state accessing various\nfields eg. hci_conn::hdev is invalid, which leads to KASAN crash in\nl2cap_sock_setsockopt() access of conn-\u003ehcon-\u003ehdev.\n\nCheck l2cap_chan::conn.hcon corresponds to an alive hci_conn before\ntrying to use it in l2cap_sock.c.  Hold l2cap_chan_lock() in\ngetsockopt/setsockopt to ensure it stays alive, and to avoid data races\nin l2cap_chan fields."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The UAF is reached from __sys_setsockopt/__sys_getsockopt_iter into l2cap_sock_setsockopt()/l2cap_sock_getsockopt(), which dereference chan-\u003econn-\u003ehcon-\u003ehdev after the HCI device is already gone; the trigger is the local BT_FLUSHABLE/BT_SECURITY/BT_PHY sockopt, not a received L2CAP or HCI PDU. Syzbot frees that hdev via vhci_release()-\u003ehci_unregister_dev(), which an in-range peer cannot invoke.\nAC:L - After b66774b48dd9, l2cap_chan_del() sets FLAG_DEL but leaves chan-\u003econn non-NULL, so a later setsockopt(SOL_BLUETOOTH, BT_FLUSHABLE, BT_FLUSHABLE_OFF) deterministically hits lmp_no_flush_capable(conn-\u003ehcon-\u003ehdev) on the deleted hci_conn. The attacker opens the L2CAP socket, tears down the controller (close of /dev/vhci), then issues the sockopt; no un-controllable race or rare config is required.\nPR:L - l2cap_sock_create() requires capable(CAP_NET_RAW) only for SOCK_RAW; SOCK_SEQPACKET/STREAM/DGRAM L2CAP sockets used here have no capability gate, and vhci_open() likewise has no capable() check. An unprivileged init_net user who can open /dev/vhci (or an equivalent HCI node) can create the socket, unregister the controller, and call setsockopt without real root.\nUI:N - The attacker owns both the AF_BLUETOOTH/BTPROTO_L2CAP fd and the teardown fd: they connect, close /dev/vhci so hci_conn_hash_flush()-\u003el2cap_conn_del() runs, then call setsockopt on their still-open socket. No other user must pair, mount, or click anything.\nS:U - l2cap_sock_setsockopt() is using a dangling hci_dev through l2cap_conn-\u003ehcon after hci_release_dev(); the resulting slab UAF stays inside the host kernel Bluetooth stack and does not cross a VM, IOMMU, or sandbox authority.\nC:H - KASAN reports a use-after-free/OOB read in l2cap_sock_setsockopt() of conn-\u003ehcon-\u003ehdev (lmp_no_flush_capable() reads hdev-\u003efeatures[0][6]; getsockopt BT_SECURITY/BT_PHY and L2CAP_CONNINFO also read hcon fields). The freed hci_dev slab was reused as skbuff_small_head, so spraying that object yields a kernel-memory read primitive through the dangling hdev pointer.\nI:H - The same dangling conn-\u003ehcon remains usable from setsockopt after FLAG_DEL: BT_SECURITY on an ATT socket calls smp_conn_security(conn-\u003ehcon) which touches hcon-\u003ehdev flags and hcon-\u003epending_sec_level, and BT_PHY calls hci_conn_set_phy() on that hcon. A sprayed hci_dev in place of the freed object supplies function pointers (send/reset/workqueues) for write and control-flow hijack.\nA:H - Syzbot crashed in l2cap_sock_setsockopt+0x22c3 (net/bluetooth/l2cap_sock.c:1003) with both KASAN slab-out-of-bounds and use-after-free reads of the released hci_dev after vhci_release()-\u003ehci_release_dev(). Any such UAF dereference oopses or panics the kernel and can be repeated by open/connect/close/setsockopt."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:52:59.418Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f49321c85785178214fd67f2e9b4b73d6363783b"
        },
        {
          "url": "https://git.kernel.org/stable/c/ca2c4c26498643f421d35ffe258fafbd3ed461c3"
        }
      ],
      "title": "Bluetooth: L2CAP: access chan-\u003econn safely in get/setsockopt",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90093",
    "datePublished": "2026-09-17T16:06:06.843Z",
    "dateReserved": "2026-09-11T19:38:34.786Z",
    "dateUpdated": "2026-09-18T17:52:59.418Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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FKIE_CVE-2026-90093

CVE-2026-90093 (GCVE-0-2026-90093)

Tags

Sightings

Nomenclature

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