usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate()

{
  "id": "f2be98b73eaa6633df0870570f4d2eb71e20c254561bf58b576f840d4e296c7a",
  "url": "https://osv.dev/vulnerability/CVE-2023-52894",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate() In Google internal bug 265639009 we've received an (as yet) unreproducible crash report from an aarch64 GKI 5.10.149-android13 running device. AFAICT the source code is at: https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10 The call stack is: ncm_close() -> ncm_notify() -> ncm_do_notify() with the crash at: ncm_do_notify+0x98/0x270 Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b) Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...): // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification) 0B 0D 00 79 strh w11, [x8, #6] // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request) 6C 0A 00 B9 str w12, [x19, #8] // x10 (NULL) was read here from offset 0 of valid pointer x9 // IMHO we're reading 'cdev->gadget' and getting NULL // gadget is indeed at offset 0 of struct usb_composite_dev 2A 01 40 F9 ldr x10, [x9] // loading req->buf pointer, which is at offset 0 of struct usb_request 69 02 40 F9 ldr x9, [x19] // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed 4B 5D 40 B9 ldr w11, [x10, #0x5c] which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment: event->wLength = cpu_to_le16(8); req->length = NCM_STATUS_BYTECOUNT; /* SPEED_CHANGE data is up/down speeds in b",
    "evidence": "osv:CVE-2023-52894",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.14.304",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "4.19.271",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.4.230",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.10.165",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.90",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2023-52894",
      "aliases": [
        "CVE-2023-52894"
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
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                  "fixed": "fef6b29671b66dfb71f17e337c1ad14b5a2cedae"
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                {
                  "fixed": "63d161f29cd39c050e8873aa36e0c9fc013bb763"
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                {
                  "fixed": "a21da7f7aae618c785f7e4a275d43c06dc8412b6"
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                  "fixed": "e92c70059178da751e5af7de02384b7dfadb5ec7"
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                  "fixed": "a69c8dfb85b44be9cc223be07d35cc3a9baefbea"
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                {
                  "fixed": "09e4507ec8ef2d44da6ba4092b8ee2d81f216497"
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                {
                  "fixed": "c6ec929595c7443250b2a4faea988c62019d5cd2"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-52894.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.9.0"
                },
                {
                  "fixed": "4.14.304"
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              ]
            },
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              "type": "ECOSYSTEM",
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                  "introduced": "5.11.0"
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              "type": "ECOSYSTEM",
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                  "introduced": "5.16.0"
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                {
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-52894.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.080793722Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/09e4507ec8ef2d44da6ba4092b8ee2d81f216497",
        "https://git.kernel.org/stable/c/63d161f29cd39c050e8873aa36e0c9fc013bb763",
        "https://git.kernel.org/stable/c/a21da7f7aae618c785f7e4a275d43c06dc8412b6",
        "https://git.kernel.org/stable/c/a69c8dfb85b44be9cc223be07d35cc3a9baefbea",
        "https://git.kernel.org/stable/c/c6ec929595c7443250b2a4faea988c62019d5cd2",
        "https://git.kernel.org/stable/c/e92c70059178da751e5af7de02384b7dfadb5ec7",
        "https://git.kernel.org/stable/c/fef6b29671b66dfb71f17e337c1ad14b5a2cedae",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/52xxx/CVE-2023-52894.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-52894",
        "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/2023/52xxx/CVE-2023-52894.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-52894",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 496922,
  "published_at": "2024-08-21T06:10:34.12+00:00"
}