usb: gadget: f_tcm: synchronize delayed set_alt with teardown

{
  "id": "58520f0b5cdeafbd631e5a9d6e512549d5cede38bb4aa28c8e02a6f1da607eea",
  "url": "https://osv.dev/vulnerability/CVE-2026-68367",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "usb: gadget: f_tcm: synchronize delayed set_alt with teardown",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: synchronize delayed set_alt with teardown The f_tcm set_alt() path defers endpoint setup to a work item and completes the delayed status response from process context. The delayed work uses f_tcm private state and may complete the setup request after disconnect or function teardown has already moved on. Cancel and drain the delayed set_alt work when the function is unbound or freed. For disable paths, which are reached under the composite device lock, use a small state machine and a non-sleeping cancellation path instead of cancel_work_sync(). If the work is already running, mark it cancelled and let the worker own the cleanup; otherwise tcm_disable() can cancel the queued work and clean up immediately. Also serialize the final delayed-status completion with the cancellation check while holding the composite device lock. This prevents a disconnect from clearing delayed_status while the worker is about to complete the control request. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in tcm_delayed_set_alt+0x6c/0xef0 Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? tcm_delayed_set_alt+0x6c/0xef0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? tcm_delayed_set_alt+0x6c/0xef0 kasan_report+0xe0/0x110 ? tcm_delayed_set_alt+0x6c/0xef0 tcm_delayed_set_alt+0x6c/0xef0 ? __pfx_tcm_delayed_set_alt+0x10/0x10 ? process_one_work+0x4cb/0xb90 ? ",
    "evidence": "osv:CVE-2026-68367",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.266",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.217",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.184",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.151",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.12.103",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.18.42",
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          {
            "value": "7.1.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-68367",
      "aliases": [
        "CVE-2026-68367"
      ],
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              "type": "GIT",
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                {
                  "fixed": "90431d8523c0c1c9f8e3e3f0895727063f93da85"
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                  "fixed": "ee07d09419f1c59c74f73107aa08444f2f2fc6c8"
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        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
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                  "introduced": "3.5.0"
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          "package": {
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            "ecosystem": "Linux"
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          "database_specific": {
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      ],
      "modified": "2026-10-28T02:30:39.153000786Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3118bb872c7dff653294f193d5328a476619e04d",
        "https://git.kernel.org/stable/c/4c6c6a5588b9a2f8437fb794e852d05fa60ebe53",
        "https://git.kernel.org/stable/c/79e2d75725c85607f8a9d87ae9cace62a19f767d",
        "https://git.kernel.org/stable/c/8fb317058d165c88f3344f59439c14872c162b3c",
        "https://git.kernel.org/stable/c/90431d8523c0c1c9f8e3e3f0895727063f93da85",
        "https://git.kernel.org/stable/c/a6eb5a0ae7cd313cfd7df78decd8f43b64c68703",
        "https://git.kernel.org/stable/c/ee07d09419f1c59c74f73107aa08444f2f2fc6c8",
        "https://git.kernel.org/stable/c/f282242906c12fd476b86757afba51f211d4f959",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68367.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68367",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68367.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68367",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 506715,
  "published_at": "2026-08-10T12:03:44.6+00:00"
}