{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.6-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  sched/isolation: Defer freeing of cpumask memblock memory to initcall  When testing a linux-next kernel with commit 59bd1d914bb5 (\"memblock: warn when freeing reserved memory before memory map is initialized\"), the following warning was hit when there was a \"nohz_full\" kernel boot parameter.    Cannot free reserved memory because of deferred initialization of the memory map   WARNING: mm/memblock.c:904 at __free_reserved_area+0xde/0xf0, CPU#0: swapper/0/0     :   Call Trace:    \u003cTASK\u003e    memblock_phys_free+0xcb/0x100    housekeeping_init+0x14c/0x170    start_kernel+0x207/0x450    x86_64_start_reservations+0x24/0x30    x86_64_start_kernel+0xda/0xe0    common_startup_64+0x13e/0x141    \u003c/TASK\u003e  IOW, we shouldn't free memblock allocated memory so early in the boot process when memory map isn't fully initialized in deferred_init_memmap().  Fix it by saving the housekeeping cpumask memblock memory to be freed into a llist free list in housekeeping_init() and add a new housekeeping_late_init() helper to defer the actual freeing of memblock memory to when initcall's are being processed. The cpumask memblock memory is treated as a llist_node with the size of a \"long\" type which is also smallest cpumask size that can be allocated.  The non-atomic version of the llist APIs are used as there is no contention.  This commit depends on the presence of commit 7c2eee9c1367 (\"memblock: don't touch memblock arrays when memblock_free() is called late\") to prevent a KASAN UAF bug report [1].   [1] https://lore.kernel.org/lkml/20260505051821.1107133-1-longman@redhat.com/",
  "id": "DEBIAN-CVE-2026-93253",
  "modified": "2026-09-25T04:47:26.460394573Z",
  "published": "2026-09-24T16:17:21.640Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-93253"
    }
  ],
  "upstream": [
    "CVE-2026-93253"
  ]
}