CVE-2026-74258 (GCVE-0-2026-74258)
Vulnerability from cvelistv5
Published
2026-08-15 05:57
Modified
2026-08-17 05:45
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Guard __get_user acesss with access_ok for uprobe_multi data As reported by sashiko [1] we need to use access_ok to check the user space data bounds before we use __get-user to get it. [1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/
Impacted products
Vendor Product Version
Linux Linux Version: 89ae89f53d201143560f1e9ed4bfa62eee34f88e
Version: 89ae89f53d201143560f1e9ed4bfa62eee34f88e
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/bpf_trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c6d51ad36490013ee9df94a372d3bf794bd304d1",
              "status": "affected",
              "version": "89ae89f53d201143560f1e9ed4bfa62eee34f88e",
              "versionType": "git"
            },
            {
              "lessThan": "4d87a251d45b4a95eb4c0abcfab809c9f231258a",
              "status": "affected",
              "version": "89ae89f53d201143560f1e9ed4bfa62eee34f88e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/bpf_trace.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.6"
            },
            {
              "lessThan": "6.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Guard __get_user acesss with access_ok for uprobe_multi data\n\nAs reported by sashiko [1] we need to use access_ok to check the user\nspace data bounds before we use __get-user to get it.\n\n[1] https://lore.kernel.org/bpf/20260610145235.CB1441F00893@smtp.kernel.org/"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is in bpf_uprobe_multi_link_attach(), reached only via the local bpf(BPF_LINK_CREATE) syscall with BPF_TRACE_UPROBE_MULTI; per kernel CNA guidance BPF/uprobe link creation is Local, not network-reachable.\nAC:L - The attacker fully controls link_create.uprobe_multi offsets/ref_ctr_offsets/cookies pointers and cnt, so __get_user runs on attacker-chosen addresses without races or external conditions; repeated attempts reliably leak or fault.\nPR:L - Exploitation requires a BPF_PROG_TYPE_KPROBE program (CAP_BPF+CAP_PERFMON), routinely delegated via BPF tokens into non-init user namespaces for tracing/container workloads; this is low privilege, not init-namespace root.\nUI:N - No victim interaction is needed; the attacker loads the BPF program, issues BPF_LINK_CREATE with crafted pointers, and can read leaked data back via BPF_OBJ_GET_INFO_BY_FD on their own link.\nS:U - Impact is arbitrary kernel memory disclosure and possible host compromise within the same kernel security authority; it does not cross VM, IOMMU, or container sandbox boundaries by itself.\nC:H - Missing access_ok lets __get_user copy from kernel addresses into uprobes arrays (up to cnt*8 bytes); cookies/offsets can be exfiltrated through bpf_uprobe_multi_link_fill_link_info, giving arbitrary kernel memory read.\nI:H - Leaked kernel pointers and attacker-influenced offset/ref_ctr values feed uprobe_register() breakpoint installation, and the read primitive is standardly chained into arbitrary kernel write and privilege escalation.\nA:H - __get_user on non-userspace addresses can fault under SMAP/PAN and oops the kernel; even failed exploitation attempts can crash the host, and guidance treats serious uaccess bugs as high availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:45:07.606Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c6d51ad36490013ee9df94a372d3bf794bd304d1"
        },
        {
          "url": "https://git.kernel.org/stable/c/4d87a251d45b4a95eb4c0abcfab809c9f231258a"
        }
      ],
      "title": "bpf: Guard __get_user acesss with access_ok for uprobe_multi data",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74258",
    "datePublished": "2026-08-15T05:57:36.257Z",
    "dateReserved": "2026-08-15T05:44:03.877Z",
    "dateUpdated": "2026-08-17T05:45:07.606Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


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