net/rds: zero per-item info buffer before handing it to visitors

{
  "id": "5a417f4265d44b702f8a73ea5ec66ccd97bef995d9aa427d2ac6816337a7cd35",
  "url": "https://osv.dev/vulnerability/CVE-2026-52995",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/rds: zero per-item info buffer before handing it to visitors",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/rds: zero per-item info buffer before handing it to visitors rds_for_each_conn_info() and rds_walk_conn_path_info() both hand a caller-allocated on-stack u64 buffer to a per-connection visitor and then copy the full item_len bytes back to user space via rds_info_copy() regardless of how much of the buffer the visitor actually wrote. rds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only write a subset of their output struct when the underlying rds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl and the two GIDs via explicit memsets). Several u32 fields (max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size, cache_allocs) and the 2-byte alignment hole between sl and cache_allocs remain as whatever stack contents preceded the visitor call and are then memcpy_to_user()'d out to user space. struct rds_info_rdma_connection and struct rds6_info_rdma_connection are the only rds_info_* structs in include/uapi/linux/rds.h that are not marked __attribute__((packed)), so they have a real alignment hole. The other info visitors (rds_conn_info_visitor, rds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of their packed output struct today and are not known to be vulnerable, but a future visitor that adds a conditional write-path would have the same bug. Reproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y: a local unprivileged user opens AF_RDS, sets SO_RDS_",
    "evidence": "osv:CVE-2026-52995",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.258",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.209",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.175",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.141",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.91",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.33",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-52995",
      "aliases": [
        "CVE-2026-52995"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                {
                  "fixed": "81651e9d7dea1c048d2952f57632a042931d7b43"
                },
                {
                  "fixed": "0797b2e6901827694aa9c34c4c72118c8c97fba1"
                },
                {
                  "fixed": "5e67cc262afb384e835c3327e9d954eeaedc6a87"
                },
                {
                  "fixed": "b6ba93a7b71ed443c9843eb12d27ed86f1e52694"
                },
                {
                  "fixed": "c7cb9eed8215a790f052f49cdccf577720d2bb62"
                },
                {
                  "fixed": "91ce1bb6e4194dc2321748f68145359dcf86e350"
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                {
                  "fixed": "912ba2e5704fdb8bc5decda96dfc1a57838f0099"
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                {
                  "fixed": "c88eb7e8d8397a8c1db59c425332c5a30b2a1682"
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              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-52995.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "2.6.30"
                },
                {
                  "fixed": "5.10.258"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
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                {
                  "fixed": "5.15.209"
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              "type": "ECOSYSTEM",
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                  "introduced": "6.7.0"
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                {
                  "fixed": "6.12.91"
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              ]
            },
            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.13.0"
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                {
                  "fixed": "6.18.33"
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            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.19.0"
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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-2026-52995.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.967162105Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0797b2e6901827694aa9c34c4c72118c8c97fba1",
        "https://git.kernel.org/stable/c/5e67cc262afb384e835c3327e9d954eeaedc6a87",
        "https://git.kernel.org/stable/c/81651e9d7dea1c048d2952f57632a042931d7b43",
        "https://git.kernel.org/stable/c/912ba2e5704fdb8bc5decda96dfc1a57838f0099",
        "https://git.kernel.org/stable/c/91ce1bb6e4194dc2321748f68145359dcf86e350",
        "https://git.kernel.org/stable/c/b6ba93a7b71ed443c9843eb12d27ed86f1e52694",
        "https://git.kernel.org/stable/c/c7cb9eed8215a790f052f49cdccf577720d2bb62",
        "https://git.kernel.org/stable/c/c88eb7e8d8397a8c1db59c425332c5a30b2a1682",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52995.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-52995",
        "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/2026/52xxx/CVE-2026-52995.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-52995",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 514043,
  "published_at": "2026-06-24T16:29:08.229+00:00"
}