CVE-2026-89526 (GCVE-0-2026-89526)
Vulnerability from cvelistv5
Published
2026-09-11 19:44
Modified
2026-10-21 12:47
Severity ?
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: svcrdma: Validate Read chunk positions before reconstruction The RPC/RDMA Read chunk position field is supplied by the remote client and stored verbatim in the parsed chunk list. xdr_count_read_segments() checks only 4-byte alignment; it never compares the position against the received inline body length. In the single-chunk path, svc_rdma_read_complete_one() splits the head and tail kvecs at ch_position. A position past the inline body underflows the tail length, exposing adjacent slab memory to the upper XDR decoder. In the multi-chunk path, svc_rdma_read_multiple_chunks() computes gap lengths between chunks as unsigned subtractions from ch_position. Overlapping Read chunks cause these subtractions to underflow. A final position past the inline body likewise underflows the trailing gap length. svc_rdma_copy_inline_range() then copies past the receive buffer into request pages that are returned to the client through the Reply channel. Bound inline-range copies in svc_rdma_copy_inline_range() against the decoded inline RPC body saved in rc_saved_arg. Reject a single Read chunk positioned beyond that body, and reject multi-chunk lists where accumulated read bytes exceed the next chunk's position. Apply the same position and overlap checks in the call-chunk interleaving path.
References
Impacted products
Vendor Product Version
Linux Linux Version: d96962e6d0e281bab6a48e83b42f5dce6eb28bf4
Version: d96962e6d0e281bab6a48e83b42f5dce6eb28bf4
Version: d96962e6d0e281bab6a48e83b42f5dce6eb28bf4
Version: d96962e6d0e281bab6a48e83b42f5dce6eb28bf4
Version: d96962e6d0e281bab6a48e83b42f5dce6eb28bf4
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-89526",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T19:22:57.126783Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-16T19:26:40.839Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_rw.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3861eeabaebe243050952b34063763527c44e1fe",
              "status": "affected",
              "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4",
              "versionType": "git"
            },
            {
              "lessThan": "5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2",
              "status": "affected",
              "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4",
              "versionType": "git"
            },
            {
              "lessThan": "f84ec84d8d4bc65f9ae23372570349687f66fa39",
              "status": "affected",
              "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4",
              "versionType": "git"
            },
            {
              "lessThan": "577097455d084610fc31e91e6a61c5793b6f04ba",
              "status": "affected",
              "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4",
              "versionType": "git"
            },
            {
              "lessThan": "3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b",
              "status": "affected",
              "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sunrpc/xprtrdma/svc_rdma_rw.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.11"
            },
            {
              "lessThan": "5.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.160",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Validate Read chunk positions before reconstruction\n\nThe RPC/RDMA Read chunk position field is supplied by the remote\nclient and stored verbatim in the parsed chunk list.\nxdr_count_read_segments() checks only 4-byte alignment; it never\ncompares the position against the received inline body length.\n\nIn the single-chunk path, svc_rdma_read_complete_one() splits the\nhead and tail kvecs at ch_position. A position past the inline\nbody underflows the tail length, exposing adjacent slab memory to\nthe upper XDR decoder.\n\nIn the multi-chunk path, svc_rdma_read_multiple_chunks() computes\ngap lengths between chunks as unsigned subtractions from\nch_position. Overlapping Read chunks cause these subtractions to\nunderflow. A final position past the inline body likewise\nunderflows the trailing gap length. svc_rdma_copy_inline_range()\nthen copies past the receive buffer into request pages that are\nreturned to the client through the Reply channel.\n\nBound inline-range copies in svc_rdma_copy_inline_range() against\nthe decoded inline RPC body saved in rc_saved_arg. Reject a\nsingle Read chunk positioned beyond that body, and reject\nmulti-chunk lists where accumulated read bytes exceed the next\nchunk\u0027s position. Apply the same position and overlap checks in\nthe call-chunk interleaving path."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - svcrdma is nfsd\u0027s RPC-over-RDMA transport; a remote peer reaches Read-chunk reconstruction on an enabled NFS/RDMA listener over routable iWARP or RoCE, consistent with prior kernel CNA scores for this subsystem.\nAC:L - The attacker fully controls the wire-supplied Read-chunk position (only 4-byte alignment is checked) and can deterministically underflow gap/tail lengths or copy past the receive buffer, with no race or uncontrollable layout required.\nPR:N - svc_rdma_process_read_list() and svc_rdma_read_complete_one() run in svc_rdma_recvfrom() while assembling the transport message, before svc_process() performs RPC or NFS authentication, and RDMA CM accept has no credential check.\nUI:N - Sending a crafted RPC-over-RDMA message with a malicious Read list is sufficient; no victim mount, click, or other user action is required.\nS:U - The vulnerable NFS/RDMA service and the affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - A position past the inline body underflows the tail kvec so the XDR decoder reads adjacent slab, and overlapping chunks make svc_rdma_copy_inline_range() memcpy past the receive buffer into request pages returned on the Reply channel, disclosing kernel memory.\nI:H - The reconstructed xdr_buf uses attacker-controlled head/tail lengths pointing into adjacent slab; XDR shift/copy helpers then memcpy through those kvecs, producing an out-of-bounds kernel write that can corrupt adjacent objects and hijack control flow.\nA:H - The unbounded inline copy and inflated kvec lengths walk unmapped memory or trip decoder/WARN paths, causing a kernel oops or panic that an unauthenticated peer can trigger repeatedly."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:47:39.359Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/3861eeabaebe243050952b34063763527c44e1fe"
        },
        {
          "url": "https://git.kernel.org/stable/c/5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2"
        },
        {
          "url": "https://git.kernel.org/stable/c/f84ec84d8d4bc65f9ae23372570349687f66fa39"
        },
        {
          "url": "https://git.kernel.org/stable/c/577097455d084610fc31e91e6a61c5793b6f04ba"
        },
        {
          "url": "https://git.kernel.org/stable/c/3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b"
        }
      ],
      "title": "svcrdma: Validate Read chunk positions before reconstruction",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89526",
    "datePublished": "2026-09-11T19:44:07.043Z",
    "dateReserved": "2026-09-11T19:38:34.719Z",
    "dateUpdated": "2026-10-21T12:47:39.359Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-89526\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-16T19:22:57.126783Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-16T19:22:58.231Z\"}}], \"cna\": {\"title\": \"svcrdma: Validate Read chunk positions before reconstruction\", \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 9.8, \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"AV:N - svcrdma is nfsd\u0027s RPC-over-RDMA transport; a remote peer reaches Read-chunk reconstruction on an enabled NFS/RDMA listener over routable iWARP or RoCE, consistent with prior kernel CNA scores for this subsystem.\\nAC:L - The attacker fully controls the wire-supplied Read-chunk position (only 4-byte alignment is checked) and can deterministically underflow gap/tail lengths or copy past the receive buffer, with no race or uncontrollable layout required.\\nPR:N - svc_rdma_process_read_list() and svc_rdma_read_complete_one() run in svc_rdma_recvfrom() while assembling the transport message, before svc_process() performs RPC or NFS authentication, and RDMA CM accept has no credential check.\\nUI:N - Sending a crafted RPC-over-RDMA message with a malicious Read list is sufficient; no victim mount, click, or other user action is required.\\nS:U - The vulnerable NFS/RDMA service and the affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\\nC:H - A position past the inline body underflows the tail kvec so the XDR decoder reads adjacent slab, and overlapping chunks make svc_rdma_copy_inline_range() memcpy past the receive buffer into request pages returned on the Reply channel, disclosing kernel memory.\\nI:H - The reconstructed xdr_buf uses attacker-controlled head/tail lengths pointing into adjacent slab; XDR shift/copy helpers then memcpy through those kvecs, producing an out-of-bounds kernel write that can corrupt adjacent objects and hijack control flow.\\nA:H - The unbounded inline copy and inflated kvec lengths walk unmapped memory or trip decoder/WARN paths, causing a kernel oops or panic that an unauthenticated peer can trigger repeatedly.\"}]}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"d96962e6d0e281bab6a48e83b42f5dce6eb28bf4\", \"lessThan\": \"3861eeabaebe243050952b34063763527c44e1fe\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d96962e6d0e281bab6a48e83b42f5dce6eb28bf4\", \"lessThan\": \"5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d96962e6d0e281bab6a48e83b42f5dce6eb28bf4\", \"lessThan\": \"f84ec84d8d4bc65f9ae23372570349687f66fa39\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d96962e6d0e281bab6a48e83b42f5dce6eb28bf4\", \"lessThan\": \"577097455d084610fc31e91e6a61c5793b6f04ba\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d96962e6d0e281bab6a48e83b42f5dce6eb28bf4\", \"lessThan\": \"3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b\", \"versionType\": \"git\"}], \"programFiles\": [\"net/sunrpc/xprtrdma/svc_rdma_rw.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"5.11\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"5.11\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"6.6.160\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.6.*\"}, {\"status\": \"unaffected\", \"version\": \"6.12.109\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.12.*\"}, {\"status\": \"unaffected\", \"version\": \"6.18.50\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.18.*\"}, {\"status\": \"unaffected\", \"version\": \"7.2.4\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"7.2.*\"}, {\"status\": \"unaffected\", \"version\": \"7.3\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"net/sunrpc/xprtrdma/svc_rdma_rw.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/3861eeabaebe243050952b34063763527c44e1fe\"}, {\"url\": \"https://git.kernel.org/stable/c/5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2\"}, {\"url\": \"https://git.kernel.org/stable/c/f84ec84d8d4bc65f9ae23372570349687f66fa39\"}, {\"url\": \"https://git.kernel.org/stable/c/577097455d084610fc31e91e6a61c5793b6f04ba\"}, {\"url\": \"https://git.kernel.org/stable/c/3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsvcrdma: Validate Read chunk positions before reconstruction\\n\\nThe RPC/RDMA Read chunk position field is supplied by the remote\\nclient and stored verbatim in the parsed chunk list.\\nxdr_count_read_segments() checks only 4-byte alignment; it never\\ncompares the position against the received inline body length.\\n\\nIn the single-chunk path, svc_rdma_read_complete_one() splits the\\nhead and tail kvecs at ch_position. A position past the inline\\nbody underflows the tail length, exposing adjacent slab memory to\\nthe upper XDR decoder.\\n\\nIn the multi-chunk path, svc_rdma_read_multiple_chunks() computes\\ngap lengths between chunks as unsigned subtractions from\\nch_position. Overlapping Read chunks cause these subtractions to\\nunderflow. A final position past the inline body likewise\\nunderflows the trailing gap length. svc_rdma_copy_inline_range()\\nthen copies past the receive buffer into request pages that are\\nreturned to the client through the Reply channel.\\n\\nBound inline-range copies in svc_rdma_copy_inline_range() against\\nthe decoded inline RPC body saved in rc_saved_arg. Reject a\\nsingle Read chunk positioned beyond that body, and reject\\nmulti-chunk lists where accumulated read bytes exceed the next\\nchunk\u0027s position. Apply the same position and overlap checks in\\nthe call-chunk interleaving path.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.6.160\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.12.109\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.18.50\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"7.2.4\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"7.3\", \"versionStartIncluding\": \"5.11\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-10-21T12:47:39.359Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-89526\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-21T12:47:39.359Z\", \"dateReserved\": \"2026-09-11T19:38:34.719Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2026-09-11T19:44:07.043Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.