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GHSA-W77G-4C35-PRWP

Vulnerability from github – Published: 2026-05-08 15:31 – Updated: 2026-05-08 15:31

Details

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: f_ncm: Fix net_device lifecycle with device_move

The network device outlived its parent gadget device during disconnection, resulting in dangling sysfs links and null pointer dereference problems.

A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1] was reverted due to power management ordering concerns and a NO-CARRIER regression.

A subsequent attempt to defer net_device allocation to bind [2] broke 1:1 mapping between function instance and network device, making it impossible for configfs to report the resolved interface name. This results in a regression where the DHCP server fails on pmOS.

Use device_move to reparent the net_device between the gadget device and /sys/devices/virtual/ across bind/unbind cycles. This preserves the network interface across USB reconnection, allowing the DHCP server to retain their binding.

Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use __free(detach_gadget) macro to undo attachment on bind failure. The bind_count ensures device_move executes only on the first bind.

[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/ [2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/

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{
  "affected": [],
  "aliases": [
    "CVE-2026-43421"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-08T15:16:54Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: Fix net_device lifecycle with device_move\n\nThe network device outlived its parent gadget device during\ndisconnection, resulting in dangling sysfs links and null pointer\ndereference problems.\n\nA prior attempt to solve this by removing SET_NETDEV_DEV entirely [1]\nwas reverted due to power management ordering concerns and a NO-CARRIER\nregression.\n\nA subsequent attempt to defer net_device allocation to bind [2] broke\n1:1 mapping between function instance and network device, making it\nimpossible for configfs to report the resolved interface name. This\nresults in a regression where the DHCP server fails on pmOS.\n\nUse device_move to reparent the net_device between the gadget device and\n/sys/devices/virtual/ across bind/unbind cycles. This preserves the\nnetwork interface across USB reconnection, allowing the DHCP server to\nretain their binding.\n\nIntroduce gether_attach_gadget()/gether_detach_gadget() helpers and use\n__free(detach_gadget) macro to undo attachment on bind failure. The\nbind_count ensures device_move executes only on the first bind.\n\n[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/\n[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/",
  "id": "GHSA-w77g-4c35-prwp",
  "modified": "2026-05-08T15:31:28Z",
  "published": "2026-05-08T15:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43421"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-43421 (GCVE-0-2026-43421)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-05-11 22:24

Title

usb: gadget: f_ncm: Fix net_device lifecycle with device_move

Summary

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: Fix net_device lifecycle with device_move The network device outlived its parent gadget device during disconnection, resulting in dangling sysfs links and null pointer dereference problems. A prior attempt to solve this by removing SET_NETDEV_DEV entirely [1] was reverted due to power management ordering concerns and a NO-CARRIER regression. A subsequent attempt to defer net_device allocation to bind [2] broke 1:1 mapping between function instance and network device, making it impossible for configfs to report the resolved interface name. This results in a regression where the DHCP server fails on pmOS. Use device_move to reparent the net_device between the gadget device and /sys/devices/virtual/ across bind/unbind cycles. This preserves the network interface across USB reconnection, allowing the DHCP server to retain their binding. Introduce gether_attach_gadget()/gether_detach_gadget() helpers and use __free(detach_gadget) macro to undo attachment on bind failure. The bind_count ensures device_move executes only on the first bind. [1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/ [2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/

Severity

No CVSS data available.

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/93f116c3393a22aca…
https://git.kernel.org/stable/c/e584cb58a2ea7ff4d…
https://git.kernel.org/stable/c/85acaba2f42b55749…
https://git.kernel.org/stable/c/ec35c1969650e7cb6…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < 93f116c3393a22acab96ad1bef12b2572eb80ca4 (git) Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d (git) Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < 85acaba2f42b557499bab3608307f17bf13beb69 (git) Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < ec35c1969650e7cb6c8a91020e568ed46e3551b0 (git)
Linux	Linux	Affected: 3.11 Unaffected: 0 , < 3.11 (semver) Unaffected: 6.12.78 , ≤ 6.12.* (semver) Unaffected: 6.18.19 , ≤ 6.18.* (semver) Unaffected: 6.19.9 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_ncm.c",
            "drivers/usb/gadget/function/u_ether.c",
            "drivers/usb/gadget/function/u_ether.h",
            "drivers/usb/gadget/function/u_ncm.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "93f116c3393a22acab96ad1bef12b2572eb80ca4",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            },
            {
              "lessThan": "e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            },
            {
              "lessThan": "85acaba2f42b557499bab3608307f17bf13beb69",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            },
            {
              "lessThan": "ec35c1969650e7cb6c8a91020e568ed46e3551b0",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_ncm.c",
            "drivers/usb/gadget/function/u_ether.c",
            "drivers/usb/gadget/function/u_ether.h",
            "drivers/usb/gadget/function/u_ncm.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.11"
            },
            {
              "lessThan": "3.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.78",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.78",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.19",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.9",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: Fix net_device lifecycle with device_move\n\nThe network device outlived its parent gadget device during\ndisconnection, resulting in dangling sysfs links and null pointer\ndereference problems.\n\nA prior attempt to solve this by removing SET_NETDEV_DEV entirely [1]\nwas reverted due to power management ordering concerns and a NO-CARRIER\nregression.\n\nA subsequent attempt to defer net_device allocation to bind [2] broke\n1:1 mapping between function instance and network device, making it\nimpossible for configfs to report the resolved interface name. This\nresults in a regression where the DHCP server fails on pmOS.\n\nUse device_move to reparent the net_device between the gadget device and\n/sys/devices/virtual/ across bind/unbind cycles. This preserves the\nnetwork interface across USB reconnection, allowing the DHCP server to\nretain their binding.\n\nIntroduce gether_attach_gadget()/gether_detach_gadget() helpers and use\n__free(detach_gadget) macro to undo attachment on bind failure. The\nbind_count ensures device_move executes only on the first bind.\n\n[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/\n[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T22:24:15.807Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4"
        },
        {
          "url": "https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d"
        },
        {
          "url": "https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69"
        },
        {
          "url": "https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0"
        }
      ],
      "title": "usb: gadget: f_ncm: Fix net_device lifecycle with device_move",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43421",
    "datePublished": "2026-05-08T14:21:56.363Z",
    "dateReserved": "2026-05-01T14:12:56.008Z",
    "dateUpdated": "2026-05-11T22:24:15.807Z",
    "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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-W77G-4C35-PRWP

CVE-2026-43421 (GCVE-0-2026-43421)

Tags

Sightings

Nomenclature