ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin()

{
  "id": "dbce2aeed99488a76ab2ac63744a96b5cdfdb5eb8a12ad27019f7b6a139e2717",
  "url": "https://osv.dev/vulnerability/CVE-2026-89491",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ocfs2: cluster: don't sleep while holding o2hb_live_lock in o2hb_region_pin() Patch series \"ocfs2: cluster: o2hb_region_pin() fixes\", v2. This series fixes three related issues in o2hb_region_pin(), all are from the original implementation in commit: 58a3158a5d17 (\"ocfs2/cluster: Pin/unpin o2hb regions\"): 1) It is called with o2hb_live_lock (a spinlock) held, but the underlying configfs_depend_item() sleeps (takes inode rwsem and pins the filesystem). This triggers BUG under CONFIG_DEBUG_ATOMIC_SLEEP. 2) When called from the configfs drop_item callback, it creates a lock order inversion: parent inode_lock -> configfs root inode_lock, which can deadlock against subsystem unregistration paths taking root -> parent. 3) If pinning fails partway through o2hb_region_inc_user(), the o2hb_dependent_users counter is leaked and partially-pinned regions are never released, leaving heartbeat regions unprotected on subsequent mounts. Patch 1 reworks o2hb_region_pin() to drop o2hb_live_lock across each sleeping configfs_depend_item() call, using a config_item reference to keep the region alive while unlocked. Patch 2 adds a from_callback parameter to select configfs_depend_item_unlocked() when called from configfs context, avoiding the inode_lock nesting. Patch 3 fixes the error path in o2hb_region_inc_user() to unpin and decrement the counter on failure. This patch (of 3): o2hb_region_pin() is always called with the o2hb_",
    "evidence": "osv:CVE-2026-89491",
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    "severity": "unknown",
    "structured": {
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      "aliases": [
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      "modified": "2026-10-28T02:30:52.119615511Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0cbc2f20a6ea7b4a59efa9171b7c694cdd196507",
        "https://git.kernel.org/stable/c/3b790774280a610f8bdbd5d4260a07345bcf8e04",
        "https://git.kernel.org/stable/c/470212a5eefabcc16b8e2f7fe2844b8737fe571c",
        "https://git.kernel.org/stable/c/49002acc520c61002ad195894ac391c94317d3ba",
        "https://git.kernel.org/stable/c/4d64f8da82fb9e8dbd5aa9b64c9bb6ac0decea03",
        "https://git.kernel.org/stable/c/af09df89db9a68a1d76df0f75667998135bc8d65",
        "https://git.kernel.org/stable/c/c9be4de77f97f383b750698e1517fd296041f4bb",
        "https://git.kernel.org/stable/c/ce035f208d68b812d83e5482980f2b1c88a9cd94",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89491.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89491",
        "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/2026/89xxx/CVE-2026-89491.json"
      }
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      {
        "value": "CVE-2026-89491",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 520939,
  "published_at": "2026-09-11T19:43:43.466+00:00"
}