{
  "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:  ftrace: fork: Initialize function graph state before copy_exec_state()  dup_task_struct() copies the parent's task_struct, including ret_stack. ftrace_graph_init_task() clears the copied function graph state, but it currently runs after copy_exec_state().  For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, copy_process() reaches bad_fork_free and free_task() calls ftrace_graph_exit_task(). Since the child still carries the parent's ret_stack pointer, the unwind frees the parent's active function graph return stack. The parent subsequently accesses freed memory from function_graph_enter_regs().  KASAN reports:  [   22.190920] ================================================================== [   22.195899] BUG: KASAN: slab-use-after-free in function_graph_enter_regs+0xa76/0xb90 [   22.200747] Write of size 8 at addr ff110000054dc0a8 by task repro/1 [   22.205134] [   22.210770] CPU: 0 UID: 0 PID: 1 Comm: repro Not tainted 7.2.0-07732-g9328b3b03bdc-dirty #3 PREEMPT(lazy) [   22.212576] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [   22.213750] Call Trace: [   22.215271]  \u003cTASK\u003e [   22.216242]  ? ftrace_stub_direct_tramp+0x10/0x10 [   22.217774]  dump_stack_lvl+0x4e/0x70 [   22.220531]  print_report+0x157/0x4b4 [   22.223202]  ? fixup_red_left+0x9/0x30 [   22.224407]  ? complete_report_info+0x83/0x110 [   22.226679]  ? function_graph_enter_regs+0xa76/0xb90 [   22.228084]  kasan_report+0xce/0x100 [   22.230109]  ? function_graph_enter_regs+0xa76/0xb90 [   22.232860]  ? stack_trace_save+0x4/0xd0 [   22.234156]  function_graph_enter_regs+0xa76/0xb90 [   22.236090]  ? kasan_save_stack+0x30/0x50 [   22.237752]  ? __pfx_function_graph_enter_regs+0x10/0x10 [   22.238694]  ? ring_buffer_lock_reserve+0x345/0xf80 [   22.239628]  ? stack_trace_save+0x4/0xd0 [   22.242121]  ? stack_trace_save+0x4/0xd0 [   22.243588]  ftrace_graph_func+0xda/0x160 [   22.245362]  ? ftrace_stub_direct_tramp+0x10/0x10 [   22.246520]  0xffffffffa0000095 [   22.250528]  ? stack_trace_save+0x9/0xd0 [   22.251757]  ? ring_buffer_unlock_commit+0x11d/0x5c0 [   22.253152]  stack_trace_save+0x9/0xd0 [   22.254264]  kasan_save_stack+0x30/0x50 [   22.273631]  kasan_save_track+0x14/0x30 [   22.276763]  kasan_save_free_info+0x3b/0x70 [   22.278296]  __kasan_slab_free+0x43/0x70 [   22.280157]  kmem_cache_free+0xbf/0x3b0 [   22.282963]  ? ftrace_stub_direct_tramp+0x10/0x10 [   22.284001]  free_task+0xa2/0x160 [   22.285699]  ? ftrace_stub_direct_tramp+0x10/0x10 [   22.286752]  copy_process+0x2aae/0x7bc0  Initialize the child function graph state immediately after dup_task_struct(), before the first fallible operation.",
  "id": "DEBIAN-CVE-2026-97937",
  "modified": "2026-09-26T04:47:38.976551831Z",
  "published": "2026-09-25T11:17:21.080Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-97937"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-97937"
  ]
}