{
  "cveId": "CVE-2026-31715",
  "url": "https://patchblox.com/security/cve/CVE-2026-31715",
  "summary": "CVE-2026-31715 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-31715, released May 15, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "f2fs: fix UAF caused by decrementing sbi-\u003Enr_pages[] in f2fs_write_end_io()",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  f2fs: fix UAF caused by decrementing sbi-\u003Enr_pages[] in f2fs_write_end_io()  The xfstests case \u0022generic/107\u0022 and syzbot have both reported a NULL pointer dereference.  The concurrent scenario that triggers the panic is as follows:  F2FS_WB_CP_DATA write callback          umount                                         - f2fs_write_checkpoint                                          - f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA) - blk_mq_end_request  - bio_endio   - f2fs_write_end_io    : dec_page_count(sbi, F2FS_WB_CP_DATA)    : wake_up(\u0026sbi-\u003Ecp_wait)                                         - kill_f2fs_super                                          - kill_block_super                                           - f2fs_put_super                                            : iput(sbi-\u003Enode_inode)                                            : sbi-\u003Enode_inode = NULL    : f2fs_in_warm_node_list     - is_node_folio // sbi-\u003Enode_inode is NULL and panic  The root cause is that f2fs_put_super() calls iput(sbi-\u003Enode_inode) and sets sbi-\u003Enode_inode to NULL after sbi-\u003Enr_pages[F2FS_WB_CP_DATA] is decremented to zero. As a result, f2fs_in_warm_node_list() may dereference a NULL node_inode when checking whether a folio belongs to the node inode, leading to a panic.  This patch fixes the issue by calling f2fs_in_warm_node_list() before decrementing sbi-\u003Enr_pages[F2FS_WB_CP_DATA], thus preventing the use-after-free condition.",
  "published": "2026-05-01T14:16:21Z",
  "severity": "Moderate",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.0012,
  "epssPercentile": 0.01817,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-31715",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.176-1",
      "fix": "DEBIAN-CVE-2026-31715",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31715",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.86-1",
      "fix": "DEBIAN-CVE-2026-31715",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31715",
      "released": "2026-05-15T16:01:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.0.3-1",
      "fix": "DEBIAN-CVE-2026-31715",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-31715",
      "released": "2026-05-15T16:01:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}