staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()

{
  "id": "4b21a5548ebe5f691ee9bd73560484eed155607449d9e949e62365c60a17acaf",
  "url": "https://osv.dev/vulnerability/CVE-2026-90018",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr() rtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from a wireless management frame. For each candidate attribute it only checks that the fixed 4-byte attribute header (2-byte ID + 2-byte length) fits inside the IE: if (attr_ptr + 4 > wps_ie + wps_ielen) break; u16 attr_id = get_unaligned_be16(attr_ptr); u16 attr_data_len = get_unaligned_be16(attr_ptr + 2); u16 attr_len = attr_data_len + 4; attr_data_len (and therefore attr_len) is read directly from the wire and is never checked against the remaining bytes in the IE before being used as the size of: memcpy(buf_attr, attr_ptr, attr_len); Since attr_len is fully attacker controlled (0 to 65535+4), this is both a heap OOB read of wps_ie, and, more seriously, a stack buffer overflow at several call sites where buf_attr is a single-byte stack variable, e.g. rtw_get_wps_attr_content()'s callers passing WPS_ATTR_SELECTED_REGISTRAR into a stack \"u8 sr\"/\"u8 selected_registrar\" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c, drivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a beacon or probe response processed during scanning can therefore smash the stack of the parsing thread. rtw_get_wps_attr_content() itself has no independent length check and simply trusts the attr_len it gets back from rtw_get_wps_attr(), so fixing the bound here also fixes that caller. The \"a",
    "evidence": "osv:CVE-2026-90018",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
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            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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            "evidence": "/affected/1/ranges"
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          {
            "value": "7.2.5",
            "evidence": "/affected/1/ranges"
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        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-90018",
      "aliases": [
        "CVE-2026-90018"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "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": "3a6457ebf39080b87c712657fdb38f34a24fc3ff"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90018.json"
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        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "4.12.0"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90018.json"
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      ],
      "modified": "2026-10-28T02:30:25.672890716Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/34f51d196c43a42046d229de5e79025d5ca553ca",
        "https://git.kernel.org/stable/c/3a6457ebf39080b87c712657fdb38f34a24fc3ff",
        "https://git.kernel.org/stable/c/931640dfcb8cfa08f6cfb46229716d8072356420",
        "https://git.kernel.org/stable/c/99aa998dec83ba180822f70e6d48a514fc81c20d",
        "https://git.kernel.org/stable/c/a53d1ac9ce63db07943b2b2248111003851fb00f",
        "https://git.kernel.org/stable/c/fd5e24ea8373347d0352f153a66e8647337d1b10",
        "https://git.kernel.org/stable/c/ff61aa3289355dafa811550a1764691cd1f5d33b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90018.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-90018",
        "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/2026/90xxx/CVE-2026-90018.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-90018",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492506,
  "published_at": "2026-09-16T10:33:23.489+00:00"
}