Vulnerability-Lookup

BDU:2026-03285

Vulnerability from fstec - Published: 17.01.2025

Title

Уязвимость функции bpf_timer_cancel_and_free() модуля kernel/bpf/helpers.c поддержки интерпретатора BPF ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Description

Уязвимость функции bpf_timer_cancel_and_free() модуля kernel/bpf/helpers.c поддержки интерпретатора BPF ядра операционной системы Linux связана с отсутствием проверки возвращаемого значения. Эксплуатация уязвимости может позволить нарушителю вызвать отказ в обслуживании

Severity


                    
                      AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Vendor

Red Hat, Inc., Сообщество свободного программного обеспечения

Software Name

Red Hat Enterprise Linux, Linux

Software Version

9 (Red Hat Enterprise Linux), от 6.13 до 6.13.1 включительно (Linux), 10 (Red Hat Enterprise Linux), от 5.15 до 6.12.12 включительно (Linux)

Possible Mitigations

В условиях отсутствия обновлений безопасности от производителя рекомендуется придерживаться "Рекомендаций по безопасной настройке операционных систем LINUX", изложенных в методическом документе ФСТЭК России, утверждённом 25 декабря 2022 года. Использование рекомендаций: Для Linux: https://lore.kernel.org/linux-cve-announce/2025030629-CVE-2025-21825-b3bd@gregkh/ https://git.kernel.org/linus/58f038e6d209d2dd862fcf5de55407855856794d https://git.kernel.org/stable/c/33e47d9573075342a41783a55c8c67bc71246fc1 https://git.kernel.org/stable/c/fbeda3d939ca10063aafa7a77cc0f409d82cda88 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.2 Для продуктов Red Hat Inc.: https://access.redhat.com/security/cve/cve-2025-21825

Reference

https://git.kernel.org/linus/58f038e6d209d2dd862fcf5de55407855856794d https://git.kernel.org/stable/c/33e47d9573075342a41783a55c8c67bc71246fc1 https://git.kernel.org/stable/c/fbeda3d939ca10063aafa7a77cc0f409d82cda88 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13 https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.2 https://lore.kernel.org/linux-cve-announce/2025030629-CVE-2025-21825-b3bd@gregkh/ https://www.cve.org/CVERecord?id=CVE-2025-21825 https://access.redhat.com/security/cve/cve-2025-21825

CWE

CWE-99, CWE-252, CWE-253, CWE-415

JSON

To clipboard

{
  "CVSS 2.0": "AV:L/AC:H/Au:S/C:N/I:N/A:C",
  "CVSS 3.0": "AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Red Hat, Inc., \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "9 (Red Hat Enterprise Linux), \u043e\u0442 6.13 \u0434\u043e 6.13.1 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), 10 (Red Hat Enterprise Linux), \u043e\u0442 5.15 \u0434\u043e 6.12.12 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0412 \u0443\u0441\u043b\u043e\u0432\u0438\u044f\u0445 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0438\u044f \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0439 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u043e\u0442 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0443\u0435\u0442\u0441\u044f \u043f\u0440\u0438\u0434\u0435\u0440\u0436\u0438\u0432\u0430\u0442\u044c\u0441\u044f \"\u0420\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u043e \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0439 \u043d\u0430\u0441\u0442\u0440\u043e\u0439\u043a\u0435 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c LINUX\", \u0438\u0437\u043b\u043e\u0436\u0435\u043d\u043d\u044b\u0445 \u0432 \u043c\u0435\u0442\u043e\u0434\u0438\u0447\u0435\u0441\u043a\u043e\u043c \u0434\u043e\u043a\u0443\u043c\u0435\u043d\u0442\u0435 \u0424\u0421\u0422\u042d\u041a \u0420\u043e\u0441\u0441\u0438\u0438, \u0443\u0442\u0432\u0435\u0440\u0436\u0434\u0451\u043d\u043d\u043e\u043c 25 \u0434\u0435\u043a\u0430\u0431\u0440\u044f 2022 \u0433\u043e\u0434\u0430.\n\n\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\n\u0414\u043b\u044f Linux:\nhttps://lore.kernel.org/linux-cve-announce/2025030629-CVE-2025-21825-b3bd@gregkh/\nhttps://git.kernel.org/linus/58f038e6d209d2dd862fcf5de55407855856794d\nhttps://git.kernel.org/stable/c/33e47d9573075342a41783a55c8c67bc71246fc1\nhttps://git.kernel.org/stable/c/fbeda3d939ca10063aafa7a77cc0f409d82cda88\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.2\n\n\u0414\u043b\u044f \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u043e\u0432 Red Hat Inc.:\nhttps://access.redhat.com/security/cve/cve-2025-21825",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "17.01.2025",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "17.03.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "17.03.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-03285",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2025-21825",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Red Hat Enterprise Linux, Linux",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": "Red Hat, Inc. Red Hat Enterprise Linux 9 , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 6.13 \u0434\u043e 6.13.1 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , Red Hat, Inc. Red Hat Enterprise Linux 10 , \u0421\u043e\u043e\u0431\u0449\u0435\u0441\u0442\u0432\u043e \u0441\u0432\u043e\u0431\u043e\u0434\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f Linux \u043e\u0442 5.15 \u0434\u043e 6.12.12 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e ",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 bpf_timer_cancel_and_free() \u043c\u043e\u0434\u0443\u043b\u044f kernel/bpf/helpers.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0438\u043d\u0442\u0435\u0440\u043f\u0440\u0435\u0442\u0430\u0442\u043e\u0440\u0430 BPF \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u0432\u0435\u0440\u043d\u043e\u0435 \u0443\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 \u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u0430\u043c\u0438 \u0440\u0435\u0441\u0443\u0440\u0441\u0430 (\u0412\u043d\u0435\u0434\u0440\u0435\u043d\u0438\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u0430) (CWE-99), \u041d\u0435\u043f\u0440\u043e\u0432\u0435\u0440\u0435\u043d\u043d\u043e\u0435 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u043c\u043e\u0435 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 (CWE-252), \u041d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u0430\u044f \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u043c\u043e\u0433\u043e \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u0438 (CWE-253), \u041f\u043e\u0432\u0442\u043e\u0440\u043d\u043e\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0435\u043d\u0438\u0435 (CWE-415)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 bpf_timer_cancel_and_free() \u043c\u043e\u0434\u0443\u043b\u044f kernel/bpf/helpers.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0438\u043d\u0442\u0435\u0440\u043f\u0440\u0435\u0442\u0430\u0442\u043e\u0440\u0430 BPF \u044f\u0434\u0440\u0430 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u043e\u0439 \u0441\u0438\u0441\u0442\u0435\u043c\u044b Linux \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043e\u0442\u0441\u0443\u0442\u0441\u0442\u0432\u0438\u0435\u043c \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0438 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u043c\u043e\u0433\u043e \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u044f. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u043e\u0442\u043a\u0430\u0437 \u0432 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u043d\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041c\u0430\u043d\u0438\u043f\u0443\u043b\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0442\u0440\u0443\u043a\u0442\u0443\u0440\u0430\u043c\u0438 \u0434\u0430\u043d\u043d\u044b\u0445, \u0418\u043d\u044a\u0435\u043a\u0446\u0438\u044f",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://git.kernel.org/linus/58f038e6d209d2dd862fcf5de55407855856794d\nhttps://git.kernel.org/stable/c/33e47d9573075342a41783a55c8c67bc71246fc1\nhttps://git.kernel.org/stable/c/fbeda3d939ca10063aafa7a77cc0f409d82cda88\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.13\nhttps://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.2\nhttps://lore.kernel.org/linux-cve-announce/2025030629-CVE-2025-21825-b3bd@gregkh/\nhttps://www.cve.org/CVERecord?id=CVE-2025-21825\nhttps://access.redhat.com/security/cve/cve-2025-21825",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041e\u043f\u0435\u0440\u0430\u0446\u0438\u043e\u043d\u043d\u0430\u044f \u0441\u0438\u0441\u0442\u0435\u043c\u0430",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-99, CWE-252, CWE-253, CWE-415",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041d\u0438\u0437\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 3,8)\n\u0421\u0440\u0435\u0434\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 4,7)"
}

CVE-2025-21825 (GCVE-0-2025-21825)

Vulnerability from cvelistv5 – Published: 2025-03-06 16:04 – Updated: 2026-08-05 11:54

Title

bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT During the update procedure, when overwrite element in a pre-allocated htab, the freeing of old_element is protected by the bucket lock. The reason why the bucket lock is necessary is that the old_element has already been stashed in htab->extra_elems after alloc_htab_elem() returns. If freeing the old_element after the bucket lock is unlocked, the stashed element may be reused by concurrent update procedure and the freeing of old_element will run concurrently with the reuse of the old_element. However, the invocation of check_and_free_fields() may acquire a spin-lock which violates the lockdep rule because its caller has already held a raw-spin-lock (bucket lock). The following warning will be reported when such race happens: BUG: scheduling while atomic: test_progs/676/0x00000003 3 locks held by test_progs/676: #0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830 #1: ffff88810e961188 (&htab->lockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500 #2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0 Modules linked in: bpf_testmod(O) Preemption disabled at: [<ffffffff817837a3>] htab_map_update_elem+0x293/0x1500 CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11 Tainted: [W]=WARN, [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)... Call Trace: <TASK> dump_stack_lvl+0x57/0x70 dump_stack+0x10/0x20 __schedule_bug+0x120/0x170 __schedule+0x300c/0x4800 schedule_rtlock+0x37/0x60 rtlock_slowlock_locked+0x6d9/0x54c0 rt_spin_lock+0x168/0x230 hrtimer_cancel_wait_running+0xe9/0x1b0 hrtimer_cancel+0x24/0x30 bpf_timer_delete_work+0x1d/0x40 bpf_timer_cancel_and_free+0x5e/0x80 bpf_obj_free_fields+0x262/0x4a0 check_and_free_fields+0x1d0/0x280 htab_map_update_elem+0x7fc/0x1500 bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43 bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e bpf_prog_test_run_syscall+0x322/0x830 __sys_bpf+0x135d/0x3ca0 __x64_sys_bpf+0x75/0xb0 x64_sys_call+0x1b5/0xa10 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... </TASK> It seems feasible to break the reuse and refill of per-cpu extra_elems into two independent parts: reuse the per-cpu extra_elems with bucket lock being held and refill the old_element as per-cpu extra_elems after the bucket lock is unlocked. However, it will make the concurrent overwrite procedures on the same CPU return unexpected -E2BIG error when the map is full. Therefore, the patch fixes the lock problem by breaking the cancelling of bpf_timer into two steps for PREEMPT_RT: 1) use hrtimer_try_to_cancel() and check its return value 2) if the timer is running, use hrtimer_cancel() through a kworker to cancel it again Considering that the current implementation of hrtimer_cancel() will try to acquire a being held softirq_expiry_lock when the current timer is running, these steps above are reasonable. However, it also has downside. When the timer is running, the cancelling of the timer is delayed when releasing the last map uref. The delay is also fixable (e.g., break the cancelling of bpf timer into two parts: one part in locked scope, another one in unlocked scope), it can be revised later if necessary. It is a bit hard to decide the right fix tag. One reason is that the problem depends on PREEMPT_RT which is enabled in v6.12. Considering the softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced in v5.15, the bpf_timer commit is used in the fixes tag and an extra depends-on tag is added to state the dependency on PREEMPT_RT. Depends-on: v6.12+ with PREEMPT_RT enabled

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/33e47d9573075342a…
https://git.kernel.org/stable/c/fbeda3d939ca10063…
https://git.kernel.org/stable/c/58f038e6d209d2dd8…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: b00628b1c7d595ae5b544e059c27b1f5828314b4 , < 33e47d9573075342a41783a55c8c67bc71246fc1 (git) Affected: b00628b1c7d595ae5b544e059c27b1f5828314b4 , < fbeda3d939ca10063aafa7a77cc0f409d82cda88 (git) Affected: b00628b1c7d595ae5b544e059c27b1f5828314b4 , < 58f038e6d209d2dd862fcf5de55407855856794d (git)
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 6.12.13 , ≤ 6.12.* (semver) Unaffected: 6.13.2 , ≤ 6.13.* (semver) Unaffected: 6.14 , ≤ * (original_commit_for_fix)

Show details on NVD website

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/helpers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "33e47d9573075342a41783a55c8c67bc71246fc1",
              "status": "affected",
              "version": "b00628b1c7d595ae5b544e059c27b1f5828314b4",
              "versionType": "git"
            },
            {
              "lessThan": "fbeda3d939ca10063aafa7a77cc0f409d82cda88",
              "status": "affected",
              "version": "b00628b1c7d595ae5b544e059c27b1f5828314b4",
              "versionType": "git"
            },
            {
              "lessThan": "58f038e6d209d2dd862fcf5de55407855856794d",
              "status": "affected",
              "version": "b00628b1c7d595ae5b544e059c27b1f5828314b4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/helpers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.13",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.13.2",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.14",
                  "versionStartIncluding": "5.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Cancel the running bpf_timer through kworker for PREEMPT_RT\n\nDuring the update procedure, when overwrite element in a pre-allocated\nhtab, the freeing of old_element is protected by the bucket lock. The\nreason why the bucket lock is necessary is that the old_element has\nalready been stashed in htab-\u003eextra_elems after alloc_htab_elem()\nreturns. If freeing the old_element after the bucket lock is unlocked,\nthe stashed element may be reused by concurrent update procedure and the\nfreeing of old_element will run concurrently with the reuse of the\nold_element. However, the invocation of check_and_free_fields() may\nacquire a spin-lock which violates the lockdep rule because its caller\nhas already held a raw-spin-lock (bucket lock). The following warning\nwill be reported when such race happens:\n\n  BUG: scheduling while atomic: test_progs/676/0x00000003\n  3 locks held by test_progs/676:\n  #0: ffffffff864b0240 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830\n  #1: ffff88810e961188 (\u0026htab-\u003elockdep_key){....}-{2:2}, at: htab_map_update_elem+0x306/0x1500\n  #2: ffff8881f4eac1b8 (\u0026base-\u003esoftirq_expiry_lock){....}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0\n  Modules linked in: bpf_testmod(O)\n  Preemption disabled at:\n  [\u003cffffffff817837a3\u003e] htab_map_update_elem+0x293/0x1500\n  CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G ... 6.12.0+ #11\n  Tainted: [W]=WARN, [O]=OOT_MODULE\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)...\n  Call Trace:\n  \u003cTASK\u003e\n  dump_stack_lvl+0x57/0x70\n  dump_stack+0x10/0x20\n  __schedule_bug+0x120/0x170\n  __schedule+0x300c/0x4800\n  schedule_rtlock+0x37/0x60\n  rtlock_slowlock_locked+0x6d9/0x54c0\n  rt_spin_lock+0x168/0x230\n  hrtimer_cancel_wait_running+0xe9/0x1b0\n  hrtimer_cancel+0x24/0x30\n  bpf_timer_delete_work+0x1d/0x40\n  bpf_timer_cancel_and_free+0x5e/0x80\n  bpf_obj_free_fields+0x262/0x4a0\n  check_and_free_fields+0x1d0/0x280\n  htab_map_update_elem+0x7fc/0x1500\n  bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43\n  bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e\n  bpf_prog_test_run_syscall+0x322/0x830\n  __sys_bpf+0x135d/0x3ca0\n  __x64_sys_bpf+0x75/0xb0\n  x64_sys_call+0x1b5/0xa10\n  do_syscall_64+0x3b/0xc0\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n  ...\n  \u003c/TASK\u003e\n\nIt seems feasible to break the reuse and refill of per-cpu extra_elems\ninto two independent parts: reuse the per-cpu extra_elems with bucket\nlock being held and refill the old_element as per-cpu extra_elems after\nthe bucket lock is unlocked. However, it will make the concurrent\noverwrite procedures on the same CPU return unexpected -E2BIG error when\nthe map is full.\n\nTherefore, the patch fixes the lock problem by breaking the cancelling\nof bpf_timer into two steps for PREEMPT_RT:\n1) use hrtimer_try_to_cancel() and check its return value\n2) if the timer is running, use hrtimer_cancel() through a kworker to\n   cancel it again\nConsidering that the current implementation of hrtimer_cancel() will try\nto acquire a being held softirq_expiry_lock when the current timer is\nrunning, these steps above are reasonable. However, it also has\ndownside. When the timer is running, the cancelling of the timer is\ndelayed when releasing the last map uref. The delay is also fixable\n(e.g., break the cancelling of bpf timer into two parts: one part in\nlocked scope, another one in unlocked scope), it can be revised later if\nnecessary.\n\nIt is a bit hard to decide the right fix tag. One reason is that the\nproblem depends on PREEMPT_RT which is enabled in v6.12. Considering the\nsoftirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced\nin v5.15, the bpf_timer commit is used in the fixes tag and an extra\ndepends-on tag is added to state the dependency on PREEMPT_RT.\n\nDepends-on: v6.12+ with PREEMPT_RT enabled"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable path is entered through the bpf() syscall (BPF_MAP_UPDATE_ELEM / BPF_MAP_DELETE_ELEM on a preallocated hash map, or a BPF program performing the update), which requires local access to the system. There is no remote or adjacent-network trigger.\nAC:L - The attacker controls both sides of the race: it arms the bpf_timer, authors the callback (which can be made to run for milliseconds via bpf_loop, keeping softirq_expiry_lock held and hrtimer_try_to_cancel() returning -1 the whole time), and hammers map_update_elem from another CPU, making the hit near-deterministic \u2014 as the upstream selftest demonstrates.\nPR:L - The bpf_timer helpers and map creation are gated on bpf_token_capable(CAP_BPF), which resolves to bpf_ns_capable() and is therefore delegable into an unprivileged user namespace via a BPF token, and the overwrite itself only needs write access to the map fd (e.g. a bpffs-pinned map). This is consistent with the CNA\u0027s PR:L treatment of other BPF-subsystem CVEs.\nUI:N - The attacker performs every step itself \u2014 creating the map, arming the timer, and issuing the overwriting update. No action by any other user or administrator is needed.\nS:U - The corruption and the lockup are confined to kernel memory and the kernel\u0027s own scheduling state, within the same security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - Sleeping mid-bpf_obj_free_fields() breaks the non-preemptible window that protects htab-\u003eextra_elems, letting another task on the same CPU re-install the element while its special fields are still being torn down \u2014 yielding a use-after-free on kptr-referenced kernel objects that can be leveraged for arbitrary kernel memory disclosure.\nI:H - The same reuse window causes bpf_obj_free_fields() to xchg-and-drop kptrs and cancel timers belonging to a live map element, producing refcount underflow and double-free of refcounted kernel objects \u2014 a classic heap-corruption write primitive usable for control-flow hijack.\nA:H - The immediate symptom is a \"BUG: scheduling while atomic\" splat (a panic under panic_on_warn), and the task deschedules while holding the bucket raw spinlock with hardirqs disabled, so other CPUs spin on it indefinitely \u2014 leading to hard lockup, deadlock against the timer softirq thread, or panic from the resulting UAF."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T11:54:42.159Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/33e47d9573075342a41783a55c8c67bc71246fc1"
        },
        {
          "url": "https://git.kernel.org/stable/c/fbeda3d939ca10063aafa7a77cc0f409d82cda88"
        },
        {
          "url": "https://git.kernel.org/stable/c/58f038e6d209d2dd862fcf5de55407855856794d"
        }
      ],
      "title": "bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21825",
    "datePublished": "2025-03-06T16:04:31.576Z",
    "dateReserved": "2024-12-29T08:45:45.775Z",
    "dateUpdated": "2026-08-05T11:54:42.159Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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