blk-cgroup: save IRQ state in blkg_tryget_closest()

{
  "id": "c404c519be63c1ad2993aa7bd2be021e58ec25c0c775d57307c9c5ec7ba13713",
  "url": "https://osv.dev/vulnerability/CVE-2026-98832",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "blk-cgroup: save IRQ state in blkg_tryget_closest()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: save IRQ state in blkg_tryget_closest() bio_set_dev() associates the bio with a blkg through bio_associate_blkg(). If the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with spin_lock_irq() and releases it with spin_unlock_irq(), which unconditionally enables local interrupts. Callers may call bio_set_dev() with interrupts already disabled, e.g. dm-thin's pool_map() does so while holding pool->lock taken with spin_lock_irq(). The nested spin_unlock_irq() then enables interrupts while pool->lock is still held, so an I/O completion softirq can run on the same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio() -> complete_mapping_preparation()) and deadlock. lockdep reports this as inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage. Commit 3a762de55b4e (\"block: save irq state in blkg_lookup_create()\") fixed the same problem while the lock lived in blkg_lookup_create(), but commit 9327a865e395 (\"blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()\") moved the locking into blkg_tryget_closest() and reverted it to spin_lock_irq(). Save and restore the caller's IRQ state instead.",
    "evidence": "osv:CVE-2026-98832",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98832",
      "aliases": [
        "CVE-2026-98832"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "9327a865e395a53f67dffac4710beb1d4730495e"
                },
                {
                  "fixed": "9fcf4317384ce6758c3127a6e8914c54cbb9c8cc"
                },
                {
                  "fixed": "327c428ba79b13e4cc5253333a9d5c0aa5579bdf"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98832.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.2.0"
                },
                {
                  "fixed": "7.2.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98832.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.775511789Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/327c428ba79b13e4cc5253333a9d5c0aa5579bdf",
        "https://git.kernel.org/stable/c/9fcf4317384ce6758c3127a6e8914c54cbb9c8cc",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98832.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98832",
        "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-2026-98832.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98832",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 518162,
  "published_at": "2026-10-18T15:49:36.925+00:00"
}