blk-mq: set RQF_USE_SCHED when the operation is known

{
  "id": "44cd41b0cc3dc785241c0053c0adebf865768a7c65fed4060978d1a570aa215b",
  "url": "https://osv.dev/vulnerability/CVE-2026-98820",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "blk-mq: set RQF_USE_SCHED when the operation is known",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: blk-mq: set RQF_USE_SCHED when the operation is known The cached requests are allocated for one operation but can be handed out for another. A passthrough command has RQF_USE_SCHED cleared, so using those flags for a subsequent read/write bio will insert it into the scheduler without ->prepare_request() and frees it without ->finish_request(). For kyber, this leaks the domain token acquired at dispatch and stalls the queue. Don't set RQF_USE_SCHED based on the first operation the batch happened to be allocated for. Instead, set it after the request is claimed by an operation. Introduce a helper function, blk_mq_rq_late_init() for this, and absorb blk_mq_rq_time_init() since the two run together.",
    "evidence": "osv:CVE-2026-98820",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.56",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98820",
      "aliases": [
        "CVE-2026-98820"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "4b6a5d9cea911424e84107df8c4eb8317938d2cd"
                },
                {
                  "fixed": "790730e4d95de8356a573d4b4864486bba731863"
                },
                {
                  "fixed": "2c47ebc27fa72078e26177cd458cdaf3006a9685"
                },
                {
                  "fixed": "ab6c756f28c741d704a7c3e04814bfc3adf6f818"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98820.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.1.0"
                },
                {
                  "fixed": "6.18.56"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98820.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.237622589Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/2c47ebc27fa72078e26177cd458cdaf3006a9685",
        "https://git.kernel.org/stable/c/790730e4d95de8356a573d4b4864486bba731863",
        "https://git.kernel.org/stable/c/ab6c756f28c741d704a7c3e04814bfc3adf6f818",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98820.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98820",
        "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/2026/98xxx/CVE-2026-98820.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98820",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 493004,
  "published_at": "2026-10-18T15:49:12.251+00:00"
}