FKIE_CVE-2026-64331

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-25 10:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: usbip: vudc: fix NULL deref in vep_dequeue() vep_alloc_request() wasn't initializing vrequest->udc, so cancellations on the FunctionFS AIO path were arriving in vep_dequeue without a valid UDC reference. Since vrequest->udc is never actually properly used anywhere, we opt to remove it, and update vep_dequeue to obtain a reference to the udc with ep_to_vudc(), consistent with the other vep_ ops. AFAICT this bug has existed for ~10 years. Seems that nobody has really stressed the FunctionFS AIO path on usbip's vudc. I tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints via AIO. Before the fix, running `usbip attach` from the host would cause the guest to oops with the following backtrace: Call trace: vep_dequeue+0x1c/0xe4 (P) usb_ep_dequeue+0x14/0x20 ffs_aio_cancel+0x24/0x34 __arm64_sys_io_cancel+0xb0/0x124 do_el0_svc+0x68/0x100 el0_svc+0x18/0x5c el0t_64_sync_handler+0x98/0xdc el0t_64_sync+0x154/0x158
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/usbip/vudc.h",
            "drivers/usb/usbip/vudc_dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9858c91d9ee6a13c45311569039413729fc9b757",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "1226293ec9bed3d4cc5b05eeeb811d315ca51652",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "3750f75f29f99c0223601e2ee73ad084adec47bd",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "0025276175fbbe0dcbf3f84d090b0adee769e9d9",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "347b59e9f96719d89b6ef555d02a18ada1a5846f",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "0443e4416aa1ee97748d1ed904eaf3352c60045e",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            },
            {
              "lessThan": "c5371e0b91b24159a3ebaa61e70b0980bcf03c0a",
              "status": "affected",
              "version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/usbip/vudc.h",
            "drivers/usb/usbip/vudc_dev.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.7"
            },
            {
              "lessThan": "4.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc3",
              "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\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn\u0027t initializing vrequest-\u003eudc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest-\u003eudc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip\u0027s vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158"
    }
  ],
  "id": "CVE-2026-64331",
  "lastModified": "2026-07-25T10:17:14.813",
  "metrics": {},
  "published": "2026-07-25T10:17:14.813",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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