rds: ib: reject FRMR registration before IB connection is established

{
  "id": "3a0ba329d2b13c9609501cbee80b30ee54b54ae14a0c026268d180f99120e146",
  "url": "https://osv.dev/vulnerability/CVE-2026-31425",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "rds: ib: reject FRMR registration before IB connection is established",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: rds: ib: reject FRMR registration before IB connection is established rds_ib_get_mr() extracts the rds_ib_connection from conn->c_transport_data and passes it to rds_ib_reg_frmr() for FRWR memory registration. On a fresh outgoing connection, ic is allocated in rds_ib_conn_alloc() with i_cm_id = NULL because the connection worker has not yet called rds_ib_conn_path_connect() to create the rdma_cm_id. When sendmsg() with RDS_CMSG_RDMA_MAP is called on such a connection, the sendmsg path parses the control message before any connection establishment, allowing rds_ib_post_reg_frmr() to dereference ic->i_cm_id->qp and crash the kernel. The existing guard in rds_ib_reg_frmr() only checks for !ic (added in commit 9e630bcb7701), which does not catch this case since ic is allocated early and is always non-NULL once the connection object exists. KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:rds_ib_post_reg_frmr+0x50e/0x920 Call Trace: rds_ib_post_reg_frmr (net/rds/ib_frmr.c:167) rds_ib_map_frmr (net/rds/ib_frmr.c:252) rds_ib_reg_frmr (net/rds/ib_frmr.c:430) rds_ib_get_mr (net/rds/ib_rdma.c:615) __rds_rdma_map (net/rds/rdma.c:295) rds_cmsg_rdma_map (net/rds/rdma.c:860) rds_sendmsg (net/rds/send.c:1363) ____sys_sendmsg do_syscall_64 Add a check in rds_ib_get_mr() that verifies ic, i_cm_id, and qp are all non-NULL before proceeding with FRMR registration, mirroring the guard already pres",
    "evidence": "osv:CVE-2026-31425",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.253",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.203",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.168",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.134",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.81",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.22",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-31425",
      "aliases": [
        "CVE-2026-31425"
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                {
                  "fixed": "82e4a3b56b23b844802056c9e75a39d24169b0a4"
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                {
                  "fixed": "450ec93c0f172374acbf236f1f5f02d53650aa2d"
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                {
                  "fixed": "6b0a8de67ac0c74e1a7df92b73c862cb36780dfc"
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                {
                  "fixed": "a5bfd14c9a299e6db4add4440430ee5e010b03ad"
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                {
                  "fixed": "23e07c340c445f0ebff7757ba15434cb447eb662"
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            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31425.json"
          }
        },
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              "type": "ECOSYSTEM",
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                  "fixed": "5.10.253"
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31425.json"
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      ],
      "modified": "2026-10-28T02:30:50.959776854Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/23e07c340c445f0ebff7757ba15434cb447eb662",
        "https://git.kernel.org/stable/c/450ec93c0f172374acbf236f1f5f02d53650aa2d",
        "https://git.kernel.org/stable/c/47de5b73db3b88f45c107393f26aeba26e9e8fae",
        "https://git.kernel.org/stable/c/6b0a8de67ac0c74e1a7df92b73c862cb36780dfc",
        "https://git.kernel.org/stable/c/82e4a3b56b23b844802056c9e75a39d24169b0a4",
        "https://git.kernel.org/stable/c/a54ecccfae62c5c85259ae5ea5d9c20009519049",
        "https://git.kernel.org/stable/c/a5bfd14c9a299e6db4add4440430ee5e010b03ad",
        "https://git.kernel.org/stable/c/c506456ebf84c50ed9327473d4e9bd905def212b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31425.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31425",
        "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/2026/31xxx/CVE-2026-31425.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31425",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 519161,
  "published_at": "2026-04-13T13:40:28.911+00:00"
}