CVE-2026-89533 (GCVE-0-2026-89533)
Vulnerability from cvelistv5
Published
2026-09-11 19:44
Modified
2026-10-19 08:48
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: Fix offset arithmetic in read_chunk_range svc_rdma_read_chunk_range() walks a Read chunk's segment list to build a sub-range starting at byte offset and spanning length bytes for a Position-Zero or Call chunk. Two arithmetic defects in the per-segment loop produce wrong DMA lengths and a u32 underflow: pcl_for_each_segment(segment, chunk) { if (offset > segment->rs_length) { offset -= segment->rs_length; continue; } dummy.rs_handle = segment->rs_handle; dummy.rs_length = min_t(u32, length, segment->rs_length) - offset; dummy.rs_offset = segment->rs_offset + offset; First, the skip predicate uses '>' instead of '>='. When offset equals the segment's full rs_length, the segment is fully consumed and should be skipped, but the loop falls through into the body. The resulting dummy.rs_length is min_t(u32, length, rs_length) - rs_length, which underflows to a near-UINT_MAX u32 when length is smaller than rs_length, or is zero otherwise. Second, the length formula subtracts offset from the min_t() result rather than from segment->rs_length before the cap. For offset > 0 the segment's residual is rs_length - offset, not rs_length, so the cap must be applied to the residual. With the current bracketing, whenever length is smaller than rs_length - offset the per-segment length becomes length - offset instead of length, silently dropping offset bytes from the rebuilt chunk. Combined with the boundary case above it also enables the u32 underflow path, which propagates a huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB kmalloc_array_node() in svc_rdma_get_rw_ctxt(). Additionally, svc_rdma_read_call_chunk() can invoke this function with length == 0 when the last Read chunk ends exactly at the end of the Call chunk. With the corrected >= predicate, every segment is skipped and the function returns the initial -EINVAL, rejecting a valid request. Return success immediately when length is zero. Also break out of the loop once length is fully consumed to avoid passing zero-length segments to svc_rdma_build_read_segment(). Fix by using '>=' so a fully-consumed segment is skipped, by moving '- offset' inside min_t() so the cap is applied to the segment's residual length, by returning success for zero-length requests, and by stopping iteration when the requested range has been consumed.
References
Impacted products
Vendor Product Version
Linux Linux Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
Version: d7cc73972661be4a02a1b09f1d9b3283c6c05154
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-89533",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T19:23:13.656876Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-16T19:26:41.551Z",
          "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": "10873311f91db9454e2fadbf9866bc819e0646d9",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "cba8543c18cf42fd80fd63effb6df6ff4f7e73ce",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "6ee4dc7476b3abc92ec1d444533a559f33f59561",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "a46b35f213c2426f5d6a0458a8f7e873fc59cdfd",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "4493c96bbd0068fadf69cbae8d13426202e34cdc",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "versionType": "git"
            },
            {
              "lessThan": "4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e",
              "status": "affected",
              "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154",
              "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": "5.15.*",
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "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": "5.15.221",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.188",
                  "versionStartIncluding": "5.11",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "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: Fix offset arithmetic in read_chunk_range\n\nsvc_rdma_read_chunk_range() walks a Read chunk\u0027s segment list to\nbuild a sub-range starting at byte offset and spanning length bytes\nfor a Position-Zero or Call chunk. Two arithmetic defects in the\nper-segment loop produce wrong DMA lengths and a u32 underflow:\n\n    pcl_for_each_segment(segment, chunk) {\n            if (offset \u003e segment-\u003ers_length) {\n                    offset -= segment-\u003ers_length;\n                    continue;\n            }\n\n            dummy.rs_handle = segment-\u003ers_handle;\n            dummy.rs_length = min_t(u32, length,\n                                    segment-\u003ers_length) - offset;\n            dummy.rs_offset = segment-\u003ers_offset + offset;\n\nFirst, the skip predicate uses \u0027\u003e\u0027 instead of \u0027\u003e=\u0027. When offset\nequals the segment\u0027s full rs_length, the segment is fully consumed\nand should be skipped, but the loop falls through into the body.\nThe resulting dummy.rs_length is min_t(u32, length, rs_length) -\nrs_length, which underflows to a near-UINT_MAX u32 when length is\nsmaller than rs_length, or is zero otherwise.\n\nSecond, the length formula subtracts offset from the min_t() result\nrather than from segment-\u003ers_length before the cap. For offset \u003e 0\nthe segment\u0027s residual is rs_length - offset, not rs_length, so the\ncap must be applied to the residual. With the current bracketing,\nwhenever length is smaller than rs_length - offset the per-segment\nlength becomes length - offset instead of length, silently dropping\noffset bytes from the rebuilt chunk. Combined with the boundary\ncase above it also enables the u32 underflow path, which propagates\na huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB\nkmalloc_array_node() in svc_rdma_get_rw_ctxt().\n\nAdditionally, svc_rdma_read_call_chunk() can invoke this function\nwith length == 0 when the last Read chunk ends exactly at the end\nof the Call chunk. With the corrected \u003e= predicate, every segment\nis skipped and the function returns the initial -EINVAL, rejecting\na valid request. Return success immediately when length is zero.\nAlso break out of the loop once length is fully consumed to avoid\npassing zero-length segments to svc_rdma_build_read_segment().\n\nFix by using \u0027\u003e=\u0027 so a fully-consumed segment is skipped, by\nmoving \u0027- offset\u0027 inside min_t() so the cap is applied to the\nsegment\u0027s residual length, by returning success for zero-length\nrequests, and by stopping iteration when the requested range has\nbeen consumed."
        }
      ],
      "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 server transport; a remote peer reaches svc_rdma_read_chunk_range() by sending a Call with a Position-Zero/Call chunk and Read list over routable iWARP or RoCEv2, matching prior kernel CNA scores for this subsystem.\nAC:L - The attacker fully controls Call-chunk segment lengths and Read-chunk positions and can place a Read chunk on a segment boundary with a smaller remaining range so dummy.rs_length underflows a u32 deterministically, with no race or uncontrollable layout.\nPR:N - svc_rdma_process_read_list() runs 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 Call chunk and Read list to an already-listening NFS/RDMA service is sufficient; no victim mount, click, or other user action is required.\nS:U - The vulnerable NFS/RDMA service and affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - The underflowed length is added to rc_readbytes and, when Reads complete, svc_rdma_read_complete_pzrc() sets xdr_buf.page_len to a near-4GiB value, so XDR walks far past the rq_pages allocation and reads adjacent kernel heap as page pointers.\nI:H - XDR helpers such as xdr_buf_pages_zero() kmap and memset through that inflated page_len, writing via out-of-bounds page pointers taken from adjacent slab, a kernel integrity and control-flow hijack primitive.\nA:H - On the scatterlist path PAGE_ALIGN wrapping to 0 hits sg_alloc_table_chained(0) which BUG_ON(!nents) and panics; the huge page_len walk oopses on invalid pages, and an unauthenticated peer can repeat this per request."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:48:24.875Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/10873311f91db9454e2fadbf9866bc819e0646d9"
        },
        {
          "url": "https://git.kernel.org/stable/c/addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7"
        },
        {
          "url": "https://git.kernel.org/stable/c/cba8543c18cf42fd80fd63effb6df6ff4f7e73ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561"
        },
        {
          "url": "https://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd"
        },
        {
          "url": "https://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc"
        },
        {
          "url": "https://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e"
        }
      ],
      "title": "svcrdma: Fix offset arithmetic in read_chunk_range",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89533",
    "datePublished": "2026-09-11T19:44:12.236Z",
    "dateReserved": "2026-09-11T19:38:34.720Z",
    "dateUpdated": "2026-10-19T08:48:24.875Z",
    "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-2026-89533\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-16T19:23:13.656876Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-16T19:23:14.222Z\"}}], \"cna\": {\"title\": \"svcrdma: Fix offset arithmetic in read_chunk_range\", \"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 server transport; a remote peer reaches svc_rdma_read_chunk_range() by sending a Call with a Position-Zero/Call chunk and Read list over routable iWARP or RoCEv2, matching prior kernel CNA scores for this subsystem.\\nAC:L - The attacker fully controls Call-chunk segment lengths and Read-chunk positions and can place a Read chunk on a segment boundary with a smaller remaining range so dummy.rs_length underflows a u32 deterministically, with no race or uncontrollable layout.\\nPR:N - svc_rdma_process_read_list() runs 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 Call chunk and Read list to an already-listening NFS/RDMA service is sufficient; no victim mount, click, or other user action is required.\\nS:U - The vulnerable NFS/RDMA service and affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\\nC:H - The underflowed length is added to rc_readbytes and, when Reads complete, svc_rdma_read_complete_pzrc() sets xdr_buf.page_len to a near-4GiB value, so XDR walks far past the rq_pages allocation and reads adjacent kernel heap as page pointers.\\nI:H - XDR helpers such as xdr_buf_pages_zero() kmap and memset through that inflated page_len, writing via out-of-bounds page pointers taken from adjacent slab, a kernel integrity and control-flow hijack primitive.\\nA:H - On the scatterlist path PAGE_ALIGN wrapping to 0 hits sg_alloc_table_chained(0) which BUG_ON(!nents) and panics; the huge page_len walk oopses on invalid pages, and an unauthenticated peer can repeat this per request.\"}]}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"10873311f91db9454e2fadbf9866bc819e0646d9\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"cba8543c18cf42fd80fd63effb6df6ff4f7e73ce\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"6ee4dc7476b3abc92ec1d444533a559f33f59561\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"a46b35f213c2426f5d6a0458a8f7e873fc59cdfd\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"4493c96bbd0068fadf69cbae8d13426202e34cdc\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"d7cc73972661be4a02a1b09f1d9b3283c6c05154\", \"lessThan\": \"4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e\", \"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\": \"5.15.221\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.15.*\"}, {\"status\": \"unaffected\", \"version\": \"6.1.188\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.1.*\"}, {\"status\": \"unaffected\", \"version\": \"6.6.157\", \"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/10873311f91db9454e2fadbf9866bc819e0646d9\"}, {\"url\": \"https://git.kernel.org/stable/c/addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7\"}, {\"url\": \"https://git.kernel.org/stable/c/cba8543c18cf42fd80fd63effb6df6ff4f7e73ce\"}, {\"url\": \"https://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561\"}, {\"url\": \"https://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd\"}, {\"url\": \"https://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc\"}, {\"url\": \"https://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsvcrdma: Fix offset arithmetic in read_chunk_range\\n\\nsvc_rdma_read_chunk_range() walks a Read chunk\u0027s segment list to\\nbuild a sub-range starting at byte offset and spanning length bytes\\nfor a Position-Zero or Call chunk. Two arithmetic defects in the\\nper-segment loop produce wrong DMA lengths and a u32 underflow:\\n\\n    pcl_for_each_segment(segment, chunk) {\\n            if (offset \u003e segment-\u003ers_length) {\\n                    offset -= segment-\u003ers_length;\\n                    continue;\\n            }\\n\\n            dummy.rs_handle = segment-\u003ers_handle;\\n            dummy.rs_length = min_t(u32, length,\\n                                    segment-\u003ers_length) - offset;\\n            dummy.rs_offset = segment-\u003ers_offset + offset;\\n\\nFirst, the skip predicate uses \u0027\u003e\u0027 instead of \u0027\u003e=\u0027. When offset\\nequals the segment\u0027s full rs_length, the segment is fully consumed\\nand should be skipped, but the loop falls through into the body.\\nThe resulting dummy.rs_length is min_t(u32, length, rs_length) -\\nrs_length, which underflows to a near-UINT_MAX u32 when length is\\nsmaller than rs_length, or is zero otherwise.\\n\\nSecond, the length formula subtracts offset from the min_t() result\\nrather than from segment-\u003ers_length before the cap. For offset \u003e 0\\nthe segment\u0027s residual is rs_length - offset, not rs_length, so the\\ncap must be applied to the residual. With the current bracketing,\\nwhenever length is smaller than rs_length - offset the per-segment\\nlength becomes length - offset instead of length, silently dropping\\noffset bytes from the rebuilt chunk. Combined with the boundary\\ncase above it also enables the u32 underflow path, which propagates\\na huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB\\nkmalloc_array_node() in svc_rdma_get_rw_ctxt().\\n\\nAdditionally, svc_rdma_read_call_chunk() can invoke this function\\nwith length == 0 when the last Read chunk ends exactly at the end\\nof the Call chunk. With the corrected \u003e= predicate, every segment\\nis skipped and the function returns the initial -EINVAL, rejecting\\na valid request. Return success immediately when length is zero.\\nAlso break out of the loop once length is fully consumed to avoid\\npassing zero-length segments to svc_rdma_build_read_segment().\\n\\nFix by using \u0027\u003e=\u0027 so a fully-consumed segment is skipped, by\\nmoving \u0027- offset\u0027 inside min_t() so the cap is applied to the\\nsegment\u0027s residual length, by returning success for zero-length\\nrequests, and by stopping iteration when the requested range has\\nbeen consumed.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.15.221\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.1.188\", \"versionStartIncluding\": \"5.11\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.6.157\", \"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\": \"2026-10-19T08:48:24.875Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-89533\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-19T08:48:24.875Z\", \"dateReserved\": \"2026-09-11T19:38:34.720Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2026-09-11T19:44:12.236Z\", \"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.