Vulnerability-Lookup

FKIE_CVE-2026-23320

Vulnerability from fkie_nvd - Published: 2026-03-25 11:16 - Updated: 2026-03-25 15:41

Severity ?

Summary

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: align net_device lifecycle with bind/unbind Currently, the net_device is allocated in ncm_alloc_inst() and freed in ncm_free_inst(). This ties the network interface's lifetime to the configuration instance rather than the USB connection (bind/unbind). This decoupling causes issues when the USB gadget is disconnected where the underlying gadget device is removed. The net_device can outlive its parent, leading to dangling sysfs links and NULL pointer dereferences when accessing the freed gadget device. Problem 1: NULL pointer dereference on disconnect Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Call trace: __pi_strlen+0x14/0x150 rtnl_fill_ifinfo+0x6b4/0x708 rtmsg_ifinfo_build_skb+0xd8/0x13c rtmsg_ifinfo+0x50/0xa0 __dev_notify_flags+0x4c/0x1f0 dev_change_flags+0x54/0x70 do_setlink+0x390/0xebc rtnl_newlink+0x7d0/0xac8 rtnetlink_rcv_msg+0x27c/0x410 netlink_rcv_skb+0x134/0x150 rtnetlink_rcv+0x18/0x28 netlink_unicast+0x254/0x3f0 netlink_sendmsg+0x2e0/0x3d4 Problem 2: Dangling sysfs symlinks console:/ # ls -l /sys/class/net/ncm0 lrwxrwxrwx ... /sys/class/net/ncm0 -> /sys/devices/platform/.../gadget.0/net/ncm0 console:/ # ls -l /sys/devices/platform/.../gadget.0/net/ncm0 ls: .../gadget.0/net/ncm0: No such file or directory Move the net_device allocation to ncm_bind() and deallocation to ncm_unbind(). This ensures the network interface exists only when the gadget function is actually bound to a configuration. To support pre-bind configuration (e.g., setting interface name or MAC address via configfs), cache user-provided options in f_ncm_opts using the gether_opts structure. Apply these cached settings to the net_device upon creation in ncm_bind(). Preserve the use-after-free fix from commit 6334b8e4553c ("usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error"). Check opts->net in ncm_set_alt() and ncm_disable() to ensure gether_disconnect() runs only if a connection was established.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/188338c1827842f898761a939669cf345bdf07e2
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/56a512a9b4107079f68701e7d55da8507eb963d9
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b62076e780a2121903ecf9ffdfb89c64647cb7da

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: align net_device lifecycle with bind/unbind\n\nCurrently, the net_device is allocated in ncm_alloc_inst() and freed in\nncm_free_inst(). This ties the network interface\u0027s lifetime to the\nconfiguration instance rather than the USB connection (bind/unbind).\n\nThis decoupling causes issues when the USB gadget is disconnected where\nthe underlying gadget device is removed. The net_device can outlive its\nparent, leading to dangling sysfs links and NULL pointer dereferences\nwhen accessing the freed gadget device.\n\nProblem 1: NULL pointer dereference on disconnect\n Unable to handle kernel NULL pointer dereference at virtual address\n 0000000000000000\n Call trace:\n   __pi_strlen+0x14/0x150\n   rtnl_fill_ifinfo+0x6b4/0x708\n   rtmsg_ifinfo_build_skb+0xd8/0x13c\n   rtmsg_ifinfo+0x50/0xa0\n   __dev_notify_flags+0x4c/0x1f0\n   dev_change_flags+0x54/0x70\n   do_setlink+0x390/0xebc\n   rtnl_newlink+0x7d0/0xac8\n   rtnetlink_rcv_msg+0x27c/0x410\n   netlink_rcv_skb+0x134/0x150\n   rtnetlink_rcv+0x18/0x28\n   netlink_unicast+0x254/0x3f0\n   netlink_sendmsg+0x2e0/0x3d4\n\nProblem 2: Dangling sysfs symlinks\n console:/ # ls -l /sys/class/net/ncm0\n lrwxrwxrwx ... /sys/class/net/ncm0 -\u003e\n /sys/devices/platform/.../gadget.0/net/ncm0\n console:/ # ls -l /sys/devices/platform/.../gadget.0/net/ncm0\n ls: .../gadget.0/net/ncm0: No such file or directory\n\nMove the net_device allocation to ncm_bind() and deallocation to\nncm_unbind(). This ensures the network interface exists only when the\ngadget function is actually bound to a configuration.\n\nTo support pre-bind configuration (e.g., setting interface name or MAC\naddress via configfs), cache user-provided options in f_ncm_opts\nusing the gether_opts structure. Apply these cached settings to the\nnet_device upon creation in ncm_bind().\n\nPreserve the use-after-free fix from commit 6334b8e4553c (\"usb: gadget:\nf_ncm: Fix UAF ncm object at re-bind after usb ep transport error\").\nCheck opts-\u003enet in ncm_set_alt() and ncm_disable() to ensure\ngether_disconnect() runs only if a connection was established."
    }
  ],
  "id": "CVE-2026-23320",
  "lastModified": "2026-03-25T15:41:33.977",
  "metrics": {},
  "published": "2026-03-25T11:16:28.747",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/188338c1827842f898761a939669cf345bdf07e2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/56a512a9b4107079f68701e7d55da8507eb963d9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b62076e780a2121903ecf9ffdfb89c64647cb7da"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

CVE-2026-23320 (GCVE-0-2026-23320)

Vulnerability from cvelistv5 – Published: 2026-03-25 10:27 – Updated: 2026-03-25 10:27

Title

usb: gadget: f_ncm: align net_device lifecycle with bind/unbind

Summary

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/b62076e780a212190…
	https://git.kernel.org/stable/c/188338c1827842f89…
	https://git.kernel.org/stable/c/56a512a9b4107079f…

Impacted products

Vendor

Product

Version

Linux

Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < b62076e780a2121903ecf9ffdfb89c64647cb7da (git)
Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < 188338c1827842f898761a939669cf345bdf07e2 (git)
Affected: 40d133d7f542616cf9538508a372306e626a16e9 , < 56a512a9b4107079f68701e7d55da8507eb963d9 (git)

Linux

Affected: 3.11
Unaffected: 0 , < 3.11 (semver)
Unaffected: 6.18.17 , ≤ 6.18.* (semver)
Unaffected: 6.19.7 , ≤ 6.19.* (semver)
Unaffected: 7.0-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_ncm.c",
            "drivers/usb/gadget/function/u_ncm.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b62076e780a2121903ecf9ffdfb89c64647cb7da",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            },
            {
              "lessThan": "188338c1827842f898761a939669cf345bdf07e2",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            },
            {
              "lessThan": "56a512a9b4107079f68701e7d55da8507eb963d9",
              "status": "affected",
              "version": "40d133d7f542616cf9538508a372306e626a16e9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_ncm.c",
            "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": "6.18.*",
              "status": "unaffected",
              "version": "6.18.17",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.17",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19.7",
                  "versionStartIncluding": "3.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0-rc1",
                  "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: align net_device lifecycle with bind/unbind\n\nCurrently, the net_device is allocated in ncm_alloc_inst() and freed in\nncm_free_inst(). This ties the network interface\u0027s lifetime to the\nconfiguration instance rather than the USB connection (bind/unbind).\n\nThis decoupling causes issues when the USB gadget is disconnected where\nthe underlying gadget device is removed. The net_device can outlive its\nparent, leading to dangling sysfs links and NULL pointer dereferences\nwhen accessing the freed gadget device.\n\nProblem 1: NULL pointer dereference on disconnect\n Unable to handle kernel NULL pointer dereference at virtual address\n 0000000000000000\n Call trace:\n   __pi_strlen+0x14/0x150\n   rtnl_fill_ifinfo+0x6b4/0x708\n   rtmsg_ifinfo_build_skb+0xd8/0x13c\n   rtmsg_ifinfo+0x50/0xa0\n   __dev_notify_flags+0x4c/0x1f0\n   dev_change_flags+0x54/0x70\n   do_setlink+0x390/0xebc\n   rtnl_newlink+0x7d0/0xac8\n   rtnetlink_rcv_msg+0x27c/0x410\n   netlink_rcv_skb+0x134/0x150\n   rtnetlink_rcv+0x18/0x28\n   netlink_unicast+0x254/0x3f0\n   netlink_sendmsg+0x2e0/0x3d4\n\nProblem 2: Dangling sysfs symlinks\n console:/ # ls -l /sys/class/net/ncm0\n lrwxrwxrwx ... /sys/class/net/ncm0 -\u003e\n /sys/devices/platform/.../gadget.0/net/ncm0\n console:/ # ls -l /sys/devices/platform/.../gadget.0/net/ncm0\n ls: .../gadget.0/net/ncm0: No such file or directory\n\nMove the net_device allocation to ncm_bind() and deallocation to\nncm_unbind(). This ensures the network interface exists only when the\ngadget function is actually bound to a configuration.\n\nTo support pre-bind configuration (e.g., setting interface name or MAC\naddress via configfs), cache user-provided options in f_ncm_opts\nusing the gether_opts structure. Apply these cached settings to the\nnet_device upon creation in ncm_bind().\n\nPreserve the use-after-free fix from commit 6334b8e4553c (\"usb: gadget:\nf_ncm: Fix UAF ncm object at re-bind after usb ep transport error\").\nCheck opts-\u003enet in ncm_set_alt() and ncm_disable() to ensure\ngether_disconnect() runs only if a connection was established."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-25T10:27:14.398Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b62076e780a2121903ecf9ffdfb89c64647cb7da"
        },
        {
          "url": "https://git.kernel.org/stable/c/188338c1827842f898761a939669cf345bdf07e2"
        },
        {
          "url": "https://git.kernel.org/stable/c/56a512a9b4107079f68701e7d55da8507eb963d9"
        }
      ],
      "title": "usb: gadget: f_ncm: align net_device lifecycle with bind/unbind",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-23320",
    "datePublished": "2026-03-25T10:27:14.398Z",
    "dateReserved": "2026-01-13T15:37:45.995Z",
    "dateUpdated": "2026-03-25T10:27:14.398Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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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FKIE_CVE-2026-23320

CVE-2026-23320 (GCVE-0-2026-23320)

Tags

Sightings

Nomenclature