blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default()

{
  "id": "84e7c88d07ca279299cf9f855876a8b2b9d3e1d89872f2ce72d8f7595b118c54",
  "url": "https://osv.dev/vulnerability/CVE-2026-53319",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: blk-wbt: remove WARN_ON_ONCE from wbt_init_enable_default() wbt_init_enable_default() uses WARN_ON_ONCE to check for failures from wbt_alloc() and wbt_init(). However, both are expected failure paths: - wbt_alloc() can return NULL under memory pressure (-ENOMEM) - wbt_init() can fail with -EBUSY if wbt is already registered syzbot triggers this by injecting memory allocation failures during MTD partition creation via ioctl(BLKPG), causing a spurious warning. wbt_init_enable_default() is a best-effort initialization called from blk_register_queue() with a void return type. Failure simply means the disk operates without writeback throttling, which is harmless. Replace WARN_ON_ONCE with plain if-checks, consistent with how wbt_set_lat() in the same file already handles these failures. Add a pr_warn() for the wbt_init() failure to retain diagnostic information without triggering a full stack trace.",
    "evidence": "osv:CVE-2026-53319",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-53319",
      "aliases": [
        "CVE-2026-53319"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "41afaeeda5099d9cd07eaa7dc6c3d20c6f1dd9e9"
                },
                {
                  "fixed": "fd7a982657077469802594a5165bc30b9a55af70"
                },
                {
                  "fixed": "e9b004ff83067cdf96774b45aea4b239ace99a2f"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53319.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.0.0"
                },
                {
                  "fixed": "7.0.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53319.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.209297918Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/e9b004ff83067cdf96774b45aea4b239ace99a2f",
        "https://git.kernel.org/stable/c/fd7a982657077469802594a5165bc30b9a55af70",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53319.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53319",
        "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/2026/53xxx/CVE-2026-53319.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53319",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 505497,
  "published_at": "2026-06-26T19:41:11.269+00:00"
}