{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47512 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47512 is a high-severity denial of service vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47512 and fix it if it is affected.\n\nWhat it is: CVE-2021-47512 is a high-severity denial of service vulnerability in Linux kernel, published on 24 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47512 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-47512/ (Markdown: https://insights.sbomify.com/CVE-2021-47512/index.md)","id":"CVE-2021-47512","markdown":"https://insights.sbomify.com/CVE-2021-47512/index.md","name":"CVE-2021-47512","record":{"aliases":["DEBIAN-CVE-2021-47512","UBUNTU-CVE-2021-47512"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A flaw in the Linux kernel's fq_pie scheduler can cause a CPU stall and system hang during qdisc dismantling, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_pie: prevent dismantle issue\n\nFor some reason, fq_pie_destroy() did not copy\nworking code from pie_destroy() and other qdiscs,\nthus causing elusive bug.\n\nBefore calling del_timer_sync(\u0026q-\u003eadapt_timer),\nwe need to ensure timer will not rearm itself.\n\nrcu: INFO: rcu_preempt self-detected stall on CPU\nrcu:    0-....: (4416 ticks this GP) idle=60d/1/0x4000000000000000 softirq=10433/10434 fqs=2579\n        (t=10501 jiffies g=13085 q=3989)\nNMI backtrace for cpu 0\nCPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.16.0-rc4-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011\nCall Trace:\n \u003cIRQ\u003e\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106\n nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111\n nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62\n trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]\n rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343\n print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]\n check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]\n rcu_pending kernel/rcu/tree.c:3878 [inline]\n rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597\n update_process_times+0x16d/0x200 kernel/time/timer.c:1785\n tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226\n tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428\n __run_hrtimer kernel/time/hrtimer.c:1685 [inline]\n __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749\n hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811\n local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]\n __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103\n sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097\n \u003c/IRQ\u003e\n \u003cTASK\u003e\n asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638\nRIP: 0010:write_comp_data kernel/kcov.c:221 [inline]\nRIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1d/0x80 kernel/kcov.c:273\nCode: 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\nRSP: 0018:ffffc90000d27b28 EFLAGS: 00000246\nRAX: 0000000000000000 RBX: ffff888064bf1bf0 RCX: ffff888011928000\nRDX: ffff888011928000 RSI: ffff888011928000 RDI: 0000000000000003\nRBP: ffff888064bf1c28 R08: 0000000000000000 R09: 0000000000000000\nR10: ffffffff875d8295 R11: 0000000000000000 R12: 0000000000000000\nR13: ffff8880783dd300 R14: 0000000000000000 R15: 0000000000000000\n pie_calculate_probability+0x405/0x7c0 net/sched/sch_pie.c:418\n fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383\n call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421\n expire_timers kernel/time/timer.c:1466 [inline]\n __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734\n __run_timers kernel/time/timer.c:1715 [inline]\n run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747\n __do_softirq+0x29b/0x9c2 kernel/softirq.c:558\n run_ksoftirqd kernel/softirq.c:921 [inline]\n run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913\n smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164\n kthread+0x405/0x4f0 kernel/kthread.c:327\n ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295\n \u003c/TASK\u003e","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"net/sched: fq_pie: prevent dismantle issue","id":"CVE-2021-47512","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"net: dsa: felix: Fix memory leak in felix_setup_mmio_filtering","id":"CVE-2021-47513"},"packages":[],"prev":{"headline":"ALSA: pcm: oss: Fix negative period/buffer sizes","id":"CVE-2021-47511"},"products":["Linux"],"published":"2024-05-24","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A flaw in the Linux kernel's fq_pie scheduler can cause a CPU stall and system hang during qdisc dismantling, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2021-47512/"}