{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  apparmor: fix integer overflow in verify_tags() bounds check  verify_tags() validates the tagset table unpacked from a policy blob. For each set it reads a count and checks that advancing the index by that count stays inside sets.table[]:  \tu32 cnt = tags-\u003esets.table[i];  \tif (i+cnt \u003e= tags-\u003esets.size) {  i, cnt and sets.size are all u32, so i+cnt is evaluated modulo 2^32. sets.table[] is filled by unpack_tagsets() with aa_unpack_u32(), so every entry is a raw unbounded 32-bit word taken from the policy blob, and verify_tags() is the function that is supposed to validate it.  A count close to U32_MAX makes the sum wrap to a small value, the guard passes, and the inner loop then walks sets.table[++i] past the end of the kcalloc(size, sizeof(u32)) allocation.  Note that sets.size is bounded by 65535, because unpack_tagsets() reads it with aa_unpack_array() as a u16, so the wrap cannot be reached by growing the table; it is reached purely through the attacker-supplied count.  With sets.size = 2 and sets.table = { 0, 0xffffffff }:    i = 0: cnt = 0, guard 0 + 0 \u003e= 2 is false, inner loop does not run   i = 1: cnt = 0xffffffff, guard (1 + 0xffffffff) mod 2^32 == 0 \u003e= 2 is          false, so the guard is bypassed and the inner loop reads          sets.table[2] -- one element past a two element allocation  The walk continues until an out-of-bounds value happens to be \u003e= hdrs.size or the access faults, so a crafted policy yields an out-of-bounds read on the policy load path (aa_replace_profiles -\u003e aa_unpack -\u003e unpack_policydb -\u003e unpack_tags -\u003e verify_tags).  unpack_tags() runs before the perms and DFA tables are unpacked, so no other table needs to be well formed to reach it.  Policy load is gated by aa_may_manage_policy(), which checks CAP_MAC_ADMIN relative to the subject's own user namespace rather than the init user namespace, so with the default unprivileged_userns_apparmor_policy=1 the path is reachable from an unprivileged task in a matched-level nested namespace, not only by a globally privileged one.  Perform the addition in u64 so that it cannot wrap, restoring the intended i + cnt \u003c sets.size guarantee.",
  "id": "DEBIAN-CVE-2026-90246",
  "modified": "2026-09-18T04:47:36.404685382Z",
  "published": "2026-09-17T17:17:20.677Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-90246"
    }
  ],
  "upstream": [
    "CVE-2026-90246"
  ]
}