{
  "cveId": "CVE-2026-63815",
  "url": "https://patchblox.com/security/cve/CVE-2026-63815",
  "summary": "CVE-2026-63815 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-63815, released July 20, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  f2fs: bound i_inline_xattr_size for non-inline-x...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  f2fs: bound i_inline_xattr_size for non-inline-xattr inodes  When the flexible_inline_xattr feature is enabled, do_read_inode() loads the on-disk i_inline_xattr_size unconditionally:  \tif (f2fs_sb_has_flexible_inline_xattr(sbi)) \t\tfi-\u003Ei_inline_xattr_size = le16_to_cpu(ri-\u003Ei_inline_xattr_size);  but sanity_check_inode() only range-checks it when the inode also has the FI_INLINE_XATTR flag set.  An inode that carries an inline dentry or inline data but not FI_INLINE_XATTR -- the normal layout for an inline directory -- therefore keeps a fully attacker-controlled i_inline_xattr_size from a crafted image.  get_inline_xattr_addrs() returns that value with no flag gating, so it feeds the inode geometry:  \tMAX_INLINE_DATA()  = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1) \tNR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...) \taddrs_per_page()   = CUR_ADDRS_PER_INODE - i_inline_xattr_size  A large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY() negative, so make_dentry_ptr_inline() sets d-\u003Emax (int) to a negative value.  The inline directory walk then compares an unsigned long bit_pos against that negative d-\u003Emax, which is promoted to a huge unsigned bound, and reads far past the inline area:  \twhile (bit_pos \u003C d-\u003Emax)\t\t/* fs/f2fs/dir.c */ \t\t... test_bit_le(bit_pos, d-\u003Ebitmap) / d-\u003Edentry[bit_pos] ...  Mounting a crafted image and reading such a directory triggers an out-of-bounds read in f2fs_fill_dentries(); the same underflow also corrupts ADDRS_PER_INODE for regular files.  Validate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the flexible_inline_xattr feature is enabled -- i.e. whenever the value is loaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE bound gated on inodes that actually carry an inline xattr, so legitimate inodes with i_inline_xattr_size == 0 are still accepted.",
  "published": "2026-07-19T12:16:54Z",
  "severity": "high",
  "cvss": 8.4,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00139,
  "epssPercentile": 0.03321,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.1.180-1",
      "fix": "DEBIAN-CVE-2026-63815",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63815",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.96-1",
      "fix": "DEBIAN-CVE-2026-63815",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63815",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.1.3-1",
      "fix": "DEBIAN-CVE-2026-63815",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63815",
      "released": "2026-07-20T12:58:36Z"
    },
    {
      "platform": "linux",
      "product": "linux-6.12",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.12.100-1~deb12u1",
      "fix": "DEBIAN-CVE-2026-63815",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-63815",
      "released": "2026-07-20T12:58:36Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-10T01:44:33Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}