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CVE-2025-40093 (GCVE-0-2025-40093)

Vulnerability from cvelistv5 – Published: 2025-10-30 09:48 – Updated: 2026-08-05 12:07
VLAI
Title
usb: gadget: f_ecm: Refactor bind path to use __free()
Summary
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ecm: Refactor bind path to use __free() After an bind/unbind cycle, the ecm->notify_req is left stale. If a subsequent bind fails, the unified error label attempts to free this stale request, leading to a NULL pointer dereference when accessing ep->ops->free_request. Refactor the error handling in the bind path to use the __free() automatic cleanup mechanism.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: da741b8c56d612b5dd26ffa31341911a5fea23ee , < d3745aaef19198d0c81637a7dd50ef53c4f879b7 (git)
Affected: da741b8c56d612b5dd26ffa31341911a5fea23ee , < 070f341d86cf2c098d63e484a86c7c1d2696a868 (git)
Affected: da741b8c56d612b5dd26ffa31341911a5fea23ee , < 15b9faf53ba8719700596e7ef78879ce200e8c2e (git)
Affected: da741b8c56d612b5dd26ffa31341911a5fea23ee , < 4630c68bade82f087eaaab22e9a361da2f18d139 (git)
Affected: da741b8c56d612b5dd26ffa31341911a5fea23ee , < 42988380ac67c76bb9dff8f77d7ef3eefd50b7b5 (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.27
Unaffected: 0 , < 2.6.27 (semver)
Unaffected: 6.1.158 , ≤ 6.1.* (semver)
Unaffected: 6.6.114 , ≤ 6.6.* (semver)
Unaffected: 6.12.55 , ≤ 6.12.* (semver)
Unaffected: 6.17.5 , ≤ 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": [
            "drivers/usb/gadget/function/f_ecm.c"
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          "product": "Linux",
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.27"
            },
            {
              "lessThan": "2.6.27",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.1.158",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.55",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.17.*",
              "status": "unaffected",
              "version": "6.17.5",
              "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": "6.1.158",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.114",
                  "versionStartIncluding": "2.6.27",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              ],
              "negate": false,
              "operator": "OR"
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        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ecm: Refactor bind path to use __free()\n\nAfter an bind/unbind cycle, the ecm-\u003enotify_req is left stale. If a\nsubsequent bind fails, the unified error label attempts to free this\nstale request, leading to a NULL pointer dereference when accessing\nep-\u003eops-\u003efree_request.\n\nRefactor the error handling in the bind path to use the __free()\nautomatic cleanup mechanism."
        }
      ],
      "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 entire bind/unbind/re-bind sequence that creates and then dereferences the stale `ecm-\u003enotify_req` is driven by local writes to `/sys/kernel/config/usb_gadget/\u003cg\u003e/UDC` and the function/config symlinks; no USB host traffic, cable event, or physical port access is required, so the bug is reachable purely through local filesystem/syscall access.\nAC:L - The attacker deterministically controls every step \u2014 the successful first bind, the unbind that leaves `ecm-\u003enotify_req`/`ecm-\u003enotify` dangling, and the forced failure of the next bind by exhausting `usb_interface_id()` (MAX_CONFIG_INTERFACES) or `usb_ep_autoconfig()` via extra functions linked into the config between cycles \u2014 plus the heap spray that reclaims the freed `usb_request`. No race or condition outside attacker control is involved.\nPR:L - `gadget_dev_desc_UDC_store()` and `ecm_bind()` perform no capability check at all; access is gated only by configfs file permissions, and on Android and embedded/industrial deployments the USB gadget configfs tree is routinely delegated to non-root system/daemon accounts that switch tethering (ECM/NCM/RNDIS) functions.\nUI:N - The attacker performs all configfs writes itself; no victim action, cable plug event, or interaction with another user is needed to reach the stale free.\nS:U - The dangling-pointer free and subsequent heap corruption stay within the kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `kfree(ecm-\u003enotify_req-\u003ebuf)` reads a pointer out of the reclaimed `struct dummy_request`/`dwc3_request` slab and `usb_ep_free_request()` reads `ep-\u003eops` out of a potentially freed `struct usb_ep`, so an attacker who grooms those generic kmalloc caches gains object-overlap and arbitrary-free primitives readily converted into kernel memory disclosure.\nI:H - `kfree()` of an attacker-controlled pointer read from the freed request, a double free of the `usb_request` itself, and an indirect call through a reclaimable `ep-\u003eops` table together yield classic heap-corruption primitives leading to arbitrary write and privilege escalation.\nA:H - The directly observed effect is a kernel oops \u2014 NULL/garbage `ep-\u003eops` dereference in `usb_ep_free_request()` \u2014 and the double free independently causes slab corruption and panic, which an unprivileged holder of the configfs tree can trigger repeatedly."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:07:44.429Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d3745aaef19198d0c81637a7dd50ef53c4f879b7"
        },
        {
          "url": "https://git.kernel.org/stable/c/070f341d86cf2c098d63e484a86c7c1d2696a868"
        },
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          "url": "https://git.kernel.org/stable/c/15b9faf53ba8719700596e7ef78879ce200e8c2e"
        },
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        },
        {
          "url": "https://git.kernel.org/stable/c/42988380ac67c76bb9dff8f77d7ef3eefd50b7b5"
        }
      ],
      "title": "usb: gadget: f_ecm: Refactor bind path to use __free()",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-40093",
    "datePublished": "2025-10-30T09:48:00.807Z",
    "dateReserved": "2025-04-16T07:20:57.163Z",
    "dateUpdated": "2026-08-05T12:07:44.429Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2025-40093",
      "date": "2026-09-16",
      "epss": "0.00144",
      "percentile": "0.04025"
    },
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    "redhat_vex": {
      "aggregate_severity": "None",
      "current_release_date": "2026-06-30T10:20:59+00:00",
      "cve": "CVE-2025-40093",
      "id": "CVE-2025-40093",
      "initial_release_date": "2025-10-30T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: usb: gadget: f_ecm: Refactor bind path to use __free()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-40093.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-28T16:55:43Z",
      "cve": "CVE-2025-40093",
      "id": "CVE-2025-40093",
      "initial_release_date": "2025-10-31T00:25:11Z",
      "product_status:known_affected": "24",
      "product_status:known_not_affected": "512",
      "product_status:recommended": "6",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-40093",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-40093.json",
      "version": "16"
    }
  }
}



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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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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.