{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "5ab829f1971dc99f2aac10846c378e67fc875abc"
            },
            {
              "fixed": "930cc4f1af5a1afcd545a6ba00e38921ff8401e0"
            },
            {
              "fixed": "2f0722435ce3a844dbb66b9bb0a18229dcc8739c"
            },
            {
              "fixed": "2116c2f0a0e547615886900e2ed8c529c016499b"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.18.0"
            },
            {
              "fixed": "6.18.52"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90277.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd/md-llbitmap: prevent create failure bitmap UAF\n\nllbitmap_create() publishes mddev-\u003ebitmap before reading the bitmap\nsuperblock. This is needed because llbitmap_read_sb() can initialize a\nnew bitmap and flush it through helpers that use mddev-\u003ebitmap.\n\nIf llbitmap_read_sb() fails, the old cleanup dropped bitmap_info.mutex\nand freed llbitmap before clearing mddev-\u003ebitmap. Readers such as\n/proc/mdstat rely on bitmap_info.mutex to keep the bitmap pointer stable\nwhile collecting bitmap stats, so they could observe the stale pointer\nafter the failed create path released the mutex.\n\nClear mddev-\u003ebitmap while still holding bitmap_info.mutex, then free the\nfailed llbitmap after dropping the mutex. This makes mutex-protected\nreaders see either a live bitmap or no bitmap.",
  "id": "CVE-2026-90277",
  "modified": "2026-09-19T03:30:48.794758027Z",
  "published": "2026-09-17T16:08:09.328Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2116c2f0a0e547615886900e2ed8c529c016499b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2f0722435ce3a844dbb66b9bb0a18229dcc8739c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/930cc4f1af5a1afcd545a6ba00e38921ff8401e0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90277.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90277"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "md/md-llbitmap: prevent create failure bitmap UAF"
}