{
  "cveId": "CVE-2021-47512",
  "url": "https://patchblox.com/security/cve/CVE-2021-47512",
  "summary": "CVE-2021-47512 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47512, released May 24, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  net/sched: fq_pie: prevent dismantle issue  For...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  net/sched: fq_pie: prevent dismantle issue  For some reason, fq_pie_destroy() did not copy working code from pie_destroy() and other qdiscs, thus causing elusive bug.  Before calling del_timer_sync(\u0026q-\u003Eadapt_timer), we need to ensure timer will not rearm itself.  rcu: INFO: rcu_preempt self-detected stall on CPU rcu:    0-....: (4416 ticks this GP) idle=60d/1/0x4000000000000000 softirq=10433/10434 fqs=2579         (t=10501 jiffies g=13085 q=3989) NMI backtrace for cpu 0 CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace:  \u003CIRQ\u003E  __dump_stack lib/dump_stack.c:88 [inline]  dump_stack_lvl\u002B0xcd/0x134 lib/dump_stack.c:106  nmi_cpu_backtrace.cold\u002B0x47/0x144 lib/nmi_backtrace.c:111  nmi_trigger_cpumask_backtrace\u002B0x1b3/0x230 lib/nmi_backtrace.c:62  trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]  rcu_dump_cpu_stacks\u002B0x25e/0x3f0 kernel/rcu/tree_stall.h:343  print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]  check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]  rcu_pending kernel/rcu/tree.c:3878 [inline]  rcu_sched_clock_irq.cold\u002B0x9d/0x746 kernel/rcu/tree.c:2597  update_process_times\u002B0x16d/0x200 kernel/time/timer.c:1785  tick_sched_handle\u002B0x9b/0x180 kernel/time/tick-sched.c:226  tick_sched_timer\u002B0x1b0/0x2d0 kernel/time/tick-sched.c:1428  __run_hrtimer kernel/time/hrtimer.c:1685 [inline]  __hrtimer_run_queues\u002B0x1c0/0xe50 kernel/time/hrtimer.c:1749  hrtimer_interrupt\u002B0x31c/0x790 kernel/time/hrtimer.c:1811  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]  __sysvec_apic_timer_interrupt\u002B0x146/0x530 arch/x86/kernel/apic/apic.c:1103  sysvec_apic_timer_interrupt\u002B0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097  \u003C/IRQ\u003E  \u003CTASK\u003E  asm_sysvec_apic_timer_interrupt\u002B0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1\u002B0x1d/0x80 kernel/kcov.c:273 Code: 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 48 89 ce 4c 8b 54 24 08 \u003Ce8\u003E 4e f7 ff ff 84 c0 74 51 48 8b 81 88 15 00 00 44 8b 81 84 15 00 RSP: 0018:ffffc90000d27b28 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888064bf1bf0 RCX: ffff888011928000 RDX: ffff888011928000 RSI: ffff888011928000 RDI: 0000000000000003 RBP: ffff888064bf1c28 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff875d8295 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880783dd300 R14: 0000000000000000 R15: 0000000000000000  pie_calculate_probability\u002B0x405/0x7c0 net/sched/sch_pie.c:418  fq_pie_timer\u002B0x170/0x2a0 net/sched/sch_fq_pie.c:383  call_timer_fn\u002B0x1a5/0x6b0 kernel/time/timer.c:1421  expire_timers kernel/time/timer.c:1466 [inline]  __run_timers.part.0\u002B0x675/0xa20 kernel/time/timer.c:1734  __run_timers kernel/time/timer.c:1715 [inline]  run_timer_softirq\u002B0xb3/0x1d0 kernel/time/timer.c:1747  __do_softirq\u002B0x29b/0x9c2 kernel/softirq.c:558  run_ksoftirqd kernel/softirq.c:921 [inline]  run_ksoftirqd\u002B0x2d/0x60 kernel/softirq.c:913  smpboot_thread_fn\u002B0x645/0x9c0 kernel/smpboot.c:164  kthread\u002B0x405/0x4f0 kernel/kthread.c:327  ret_from_fork\u002B0x1f/0x30 arch/x86/entry/entry_64.S:295  \u003C/TASK\u003E",
  "published": "2024-05-24T15:15:12Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00245,
  "epssPercentile": 0.15811,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.15.15-1",
      "fix": "DEBIAN-CVE-2021-47512",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47512",
      "released": "2024-05-24T15:15:12Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.15.15-1",
      "fix": "DEBIAN-CVE-2021-47512",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47512",
      "released": "2024-05-24T15:15:12Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.15.15-1",
      "fix": "DEBIAN-CVE-2021-47512",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47512",
      "released": "2024-05-24T15:15:12Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}