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CVE-2026-90045 (GCVE-0-2026-90045)

Vulnerability from cvelistv5 – Published: 2026-09-16 10:33 – Updated: 2026-09-16 14:41
VLAI
Title
USB: gadget: ffs: fix mm lifetime handling
Summary
In the Linux kernel, the following vulnerability has been resolved: USB: gadget: ffs: fix mm lifetime handling io_data stores a pointer to the submitting task's mm_struct, but does not currently hold a reference to it while async requests are pending. This can result in a use-after-free if the task exits before completion handling finishes. Take a reference with mmgrab() when queuing the read request and release it with mmdrop() on request completion.
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f3d31484b3f26d63c09e5569ebfaa1079a17f171 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7411de0ce3b45286de1de82526795658ea6eacb0 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8 (git)
Affected: 0 , < 6.18.51 (semver)
Affected: 0 , < 7.2.5 (semver)
guessed Create a notification for this product.
Linux Linux Unaffected: 6.18.51 , ≤ 6.18.* (semver)
Unaffected: 7.2.5 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f3d31484b3f26d63c09e5569ebfaa1079a17f171",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "7411de0ce3b45286de1de82526795658ea6eacb0",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
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              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6.18.51",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "7.2.5",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.5",
              "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": "6.18.51",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: gadget: ffs: fix mm lifetime handling\n\nio_data stores a pointer to the submitting task\u0027s mm_struct,\nbut does not currently hold a reference to it while async\nrequests are pending.\n\nThis can result in a use-after-free if the task exits before\ncompletion handling finishes.\n\nTake a reference with mmgrab() when queuing the read request\nand release it with mmdrop() on request completion."
        }
      ],
      "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 via local aio_read/io_submit on FunctionFS ep files (ffs_epfile_read_iter \u2192 ffs_epfile_io), not by parsing USB host packets. This is the gadget userspace API; prior f_fs AIO UAFs (CVE-2024-36894, CVE-2025-71074) are scored Local, which is also the higher-severity vector versus Physical.\nAC:L - The attacker submits the AIO read, can complete it locally (dummy_hcd or an already-bound gadget) and exit while the ordered io_completion_wq worker is still pending. Both sides of the mm-lifetime race are attacker-driven and freely retryable, so this is not AC:H.\nPR:L - ffs_epfile_open has no capability check. FunctionFS mounts commonly set uid=/gid=/fmode= so unprivileged gadget daemons (adbd/shell, MTP) can open ep files; mounting needs init-namespace CAP_SYS_ADMIN, but using already-mounted endpoints does not.\nUI:N - The attacker performs io_submit and process exit itself. No separate victim action is required beyond an already-deployed FunctionFS gadget.\nS:U - The mm_struct use-after-free corrupts host kernel state within the same security authority. This is standard local kernel privilege escalation, not a VM, IOMMU, or sandbox escape.\nC:H - Use-after-free of mm_struct lets kthread_use_mm/switch_mm consume a reclaimed mm (including mm-\u003epgd) and copy_to_iter through attacker-influenced page tables, yielding an arbitrary read primitive. Per scoring guidance, UAF is Confidentiality High.\nI:H - kthread_use_mm on a sprayed mm_struct can install attacker-controlled page tables, and ffs_copy_to_iter then writes the USB payload through them, giving an arbitrary write and control-flow hijack primitive. Per scoring guidance, UAF is Integrity High.\nA:H - Using a freed mm_struct in kthread_use_mm/switch_mm and copy_to_iter reliably oopses or panics the kernel even without a full exploit, so availability impact is High."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:41:59.869Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/f3d31484b3f26d63c09e5569ebfaa1079a17f171"
        },
        {
          "url": "https://git.kernel.org/stable/c/7411de0ce3b45286de1de82526795658ea6eacb0"
        },
        {
          "url": "https://git.kernel.org/stable/c/5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8"
        }
      ],
      "title": "USB: gadget: ffs: fix mm lifetime handling",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90045",
    "datePublished": "2026-09-16T10:33:42.411Z",
    "dateReserved": "2026-09-11T19:38:34.783Z",
    "dateUpdated": "2026-09-16T14:41:59.869Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-90045\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-16T11:17:17.763\",\"lastModified\":\"2026-09-16T15:18:27.210\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nUSB: gadget: ffs: fix mm lifetime handling\\n\\nio_data stores a pointer to the submitting task\u0027s mm_struct,\\nbut does not currently hold a reference to it while async\\nrequests are pending.\\n\\nThis can result in a use-after-free if the task exits before\\ncompletion handling finishes.\\n\\nTake a reference with mmgrab() when queuing the read request\\nand release it with mmdrop() on request completion.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/usb/gadget/function/f_fs.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"f3d31484b3f26d63c09e5569ebfaa1079a17f171\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"7411de0ce3b45286de1de82526795658ea6eacb0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.18.51\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.2.5\",\"versionType\":\"semver\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/usb/gadget/function/f_fs.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.18.51\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.5\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/7411de0ce3b45286de1de82526795658ea6eacb0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f3d31484b3f26d63c09e5569ebfaa1079a17f171\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



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