{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "06f5c2926aaa0fba7f99678da6ef77cbbbda1441"
            },
            {
              "fixed": "38dbc8db8341ccdf8e1e1a067453d33ad751864b"
            },
            {
              "fixed": "4c5a0a946373da99a80398289b28845b5ae40cd1"
            },
            {
              "fixed": "661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"
            },
            {
              "fixed": "daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"
            },
            {
              "fixed": "98495b5a4d77dd22e106f462b76e1093a55b29a7"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.3.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncoresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()\n\nWhen the SMB sink is used as a perf AUX sink, smb_update_buffer() calls\nsmb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring\nbuffer pages. It derives pg_idx = head \u003e\u003e PAGE_SHIFT from @head, which is\nhandle-\u003ehead, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages\nnormalization is only applied after the first loop iteration.\n\nThis leaves the initial page index underived from the buffer size, which\ncan result in an out-of-bounds write past dst_pages[] when head exceeds\nthe AUX buffer size.\n\nNormalize head modulo the AUX buffer size before deriving the page index\nand offset, mirroring tmc_etr_sync_perf_buffer().",
  "id": "CVE-2026-64402",
  "modified": "2026-07-28T03:55:51.552179736Z",
  "published": "2026-07-25T08:50:45.075Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/38dbc8db8341ccdf8e1e1a067453d33ad751864b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4c5a0a946373da99a80398289b28845b5ae40cd1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/661a019ac0413ecec9e5d1dfcc12fbca8e78d5fb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/98495b5a4d77dd22e106f462b76e1093a55b29a7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/daf6246ab988fc8bdc82ad7c8d0b1c182d11b15f"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64402.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64402"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()"
}