net/rds: use wq_has_sleeper() in rds_cong_map_updated()

{
  "id": "31166b1e13f40ab4f4911899e87f8286997bb9975512f93efd92ca6629b222bf",
  "url": "https://osv.dev/vulnerability/CVE-2026-90081",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/rds: use wq_has_sleeper() in rds_cong_map_updated()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/rds: use wq_has_sleeper() in rds_cong_map_updated() rds_cong_map_updated() runs after a peer's congestion map has been rewritten (by rds_tcp_cong_recv() and rds_ib_cong_recv(), or the clear-all in the loopback and IB send-completion paths). It bumps rds_cong_generation and then checks waitqueue_active() on map->m_waitq and on rds_poll_waitq to decide whether anyone needs waking. atomic_inc() carries no ordering and waitqueue_active() is a plain load, so nothing orders the map and generation stores before the wait queue reads. The waiters do the mirror image: rds_cong_wait() adds itself to m_waitq and then tests the port bit, and rds_poll() registers on rds_poll_waitq and then reads the generation. That is the store-buffering pattern described above waitqueue_active() in include/linux/wait.h - the updater can observe an empty wait queue while the waiter still observes the port as congested, and no wake-up is issued. rds_cong_wait() is an interruptible sleep with no timeout, so a sender blocked on a congested port stays blocked until the next congestion update from that peer arrives or a signal is delivered. A poll() waiter misses the map-updated notification the same way. Use wq_has_sleeper(), which is waitqueue_active() preceded by the required full barrier, as rds_tcp_state_change() already does for the same pattern.",
    "evidence": "osv:CVE-2026-90081",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.270",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.52",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-90081",
      "aliases": [
        "CVE-2026-90081"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "922cb17a5c812fcc9ebee249f4109db099896941"
                },
                {
                  "fixed": "2a809d7896dbf18e1ecfbdd930f71c9fc298b16d"
                },
                {
                  "fixed": "fa4b98e891fda28cc0638d809c6125ec63d8319d"
                },
                {
                  "fixed": "0e169f6a2adeb17b5577ed7e8abd642465bb50ec"
                },
                {
                  "fixed": "42884bd8b8fd023d6a610a695bd5ddd1d5dece17"
                },
                {
                  "fixed": "a526214b9f0548ca0e53a6e0d1727d8ea9befc23"
                },
                {
                  "fixed": "bf2b8130723efcb5b86c3ddb6317c3a9b2a9cfc5"
                },
                {
                  "fixed": "281f9fda2e06d6c211bb365a5379ed2e05cc2e21"
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                {
                  "fixed": "d4f484661961636eb90d287050959e613795f73a"
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              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90081.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "2.6.30"
                },
                {
                  "fixed": "5.10.270"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.221"
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              ]
            },
            {
              "type": "ECOSYSTEM",
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                  "introduced": "5.16.0"
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                  "introduced": "6.2.0"
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            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.110"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.52"
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              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.6"
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              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90081.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.205187858Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0e169f6a2adeb17b5577ed7e8abd642465bb50ec",
        "https://git.kernel.org/stable/c/281f9fda2e06d6c211bb365a5379ed2e05cc2e21",
        "https://git.kernel.org/stable/c/2a809d7896dbf18e1ecfbdd930f71c9fc298b16d",
        "https://git.kernel.org/stable/c/42884bd8b8fd023d6a610a695bd5ddd1d5dece17",
        "https://git.kernel.org/stable/c/a526214b9f0548ca0e53a6e0d1727d8ea9befc23",
        "https://git.kernel.org/stable/c/bf2b8130723efcb5b86c3ddb6317c3a9b2a9cfc5",
        "https://git.kernel.org/stable/c/d4f484661961636eb90d287050959e613795f73a",
        "https://git.kernel.org/stable/c/fa4b98e891fda28cc0638d809c6125ec63d8319d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90081.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-90081",
        "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-2026-90081.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-90081",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499266,
  "published_at": "2026-09-17T16:05:58.866+00:00"
}