Vulnerability-Lookup

BDU:2025-04455 (CVE-2025-21900)

Vulnerability from fstec – Published: 2025-04-14 – Updated: 2026-02-17 – View on bdu.fstec.ru Fixed

Title

Уязвимость компонента NFSv4 функции close ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Summary

Уязвимость компонента NFSv4 функции close ядра операционной системы Linux связана с взаимной блокировкой потоков выполнения. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, вызвать отказ в обслуживании

Severity

4.3 (Medium) CVSS 2.0


                      
                        AV:A/AC:H/Au:S/C:N/I:N/A:C

4.8 (Medium) CVSS 3.1


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

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Resource exhaustion

Incidents

Being clarified

Remediation

Software update

CWE

CWE-833 - Зависание

Aliases

CVE-2025-21900

References

9 references

URL
https://vuldb.com/ru/?id.302632
https://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871
https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38
https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0
https://lore.kernel.org/linux-cve-announce/2025040133-CVE-2025-21900-8d31@gregkh/
https://access.redhat.com/security/cve/cve-2025-21900
https://ubuntu.com/security/CVE-2025-21900
https://wiki.astralinux.ru/astra-linux-se18-bulletin-2025-0811SE18
http://repo.red-soft.ru/redos/8.0/x86_64/updates/

Impacted products

6 products from 7 vendors

Vendors

Red Hat, Inc., Canonical Ltd., ООО «РусБИТех-Астра», Сообщество свободного программного обеспечения, ООО «Ред Софт», АО «СберТех»

Products

Red Hat Enterprise Linux, Ubuntu, Astra Linux Special Edition (запись в едином реестре российских программ №369), Linux, РЕД ОС (запись в едином реестре российских программ №3751), Platform V SberLinux OS Server (запись в едином реестре российских программ №18785)

Versions

9 (Red Hat Enterprise Linux), 24.04 LTS (Ubuntu), 1.8 (Astra Linux Special Edition), 24.10 (Ubuntu), от 6.11 до 6.12.18 (Linux), от 6.11 до 6.13.6 (Linux), от 6.11 до 6.14 (Linux), 8.0 (РЕД ОС), 9.2.0-fstec (Platform V SberLinux OS Server)

Product types

Operating system

Platforms

Red Hat, Inc. Red Hat Enterprise Linux 9, Canonical Ltd. Ubuntu 24.04 LTS, ООО «РусБИТех-Астра» Astra Linux Special Edition 1.8 (запись в едином реестре российских программ №369), Canonical Ltd. Ubuntu 24.10, Сообщество свободного программного обеспечения Linux от 6.11 до 6.12.18, Сообщество свободного программного обеспечения Linux от 6.11 до 6.13.6, Сообщество свободного программного обеспечения Linux от 6.11 до 6.14, ООО «Ред Софт» РЕД ОС 8.0 (запись в едином реестре российских программ №3751), АО «СберТех» Platform V SberLinux OS Server 9.2.0-fstec (запись в едином реестре российских программ №18785)

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://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871 https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38 https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0 https://lore.kernel.org/linux-cve-announce/2025040133-CVE-2025-21900-8d31@gregkh/ Для программных продуктов Red Hat Inc.: https://access.redhat.com/security/cve/cve-2025-21900 Для Ubuntu: https://ubuntu.com/security/CVE-2025-21900 Для ОС Astra Linux: обновить пакет linux-6.12 до 6.12.34-1.astra1+ci2 или более высокой версии, используя рекомендации производителя: https://wiki.astralinux.ru/astra-linux-se18-bulletin-2025-0811SE18 Для Ред ОС: http://repo.red-soft.ru/redos/8.0/x86_64/updates/

JSON

To clipboard

{
  "CVSS 2.0": "AV:A/AC:H/Au:S/C:N/I:N/A:C",
  "CVSS 3.0": "AV:A/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., Canonical Ltd., \u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb, \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, \u041e\u041e\u041e \u00ab\u0420\u0435\u0434 \u0421\u043e\u0444\u0442\u00bb, \u0410\u041e \u00ab\u0421\u0431\u0435\u0440\u0422\u0435\u0445\u00bb",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "9 (Red Hat Enterprise Linux), 24.04 LTS (Ubuntu), 1.8 (Astra Linux Special Edition), 24.10 (Ubuntu), \u043e\u0442 6.11 \u0434\u043e 6.12.18 (Linux), \u043e\u0442 6.11 \u0434\u043e 6.13.6 (Linux), \u043e\u0442 6.11 \u0434\u043e 6.14 (Linux), 8.0 (\u0420\u0415\u0414 \u041e\u0421), 9.2.0-fstec (Platform V SberLinux OS Server)",
  "\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://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871\t\nhttps://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38\t\nhttps://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0\t\nhttps://lore.kernel.org/linux-cve-announce/2025040133-CVE-2025-21900-8d31@gregkh/\n\n\u0414\u043b\u044f \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u044b\u0445 \u043f\u0440\u043e\u0434\u0443\u043a\u0442\u043e\u0432 Red Hat Inc.:\nhttps://access.redhat.com/security/cve/cve-2025-21900\n\n\u0414\u043b\u044f Ubuntu:\nhttps://ubuntu.com/security/CVE-2025-21900\n\n\u0414\u043b\u044f \u041e\u0421 Astra Linux:\n\u043e\u0431\u043d\u043e\u0432\u0438\u0442\u044c \u043f\u0430\u043a\u0435\u0442 linux-6.12 \u0434\u043e 6.12.34-1.astra1+ci2 \u0438\u043b\u0438 \u0431\u043e\u043b\u0435\u0435 \u0432\u044b\u0441\u043e\u043a\u043e\u0439 \u0432\u0435\u0440\u0441\u0438\u0438, \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044f \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0438 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f: https://wiki.astralinux.ru/astra-linux-se18-bulletin-2025-0811SE18\n\n\u0414\u043b\u044f \u0420\u0435\u0434 \u041e\u0421: \nhttp://repo.red-soft.ru/redos/8.0/x86_64/updates/\n\n\n\n",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "01.02.2025",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "17.02.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "14.04.2025",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2025-04455",
  "\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-2025-21900",
  "\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, Ubuntu, Astra Linux Special Edition (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u2116369), Linux, \u0420\u0415\u0414 \u041e\u0421 (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21163751), Platform V SberLinux OS Server (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u211618785)",
  "\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 , Canonical Ltd. Ubuntu 24.04 LTS , \u041e\u041e\u041e \u00ab\u0420\u0443\u0441\u0411\u0418\u0422\u0435\u0445-\u0410\u0441\u0442\u0440\u0430\u00bb Astra Linux Special Edition 1.8  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u2116369), Canonical Ltd. Ubuntu 24.10 , \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 6.11 \u0434\u043e 6.12.18 , \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 6.11 \u0434\u043e 6.13.6 , \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 6.11 \u0434\u043e 6.14 , \u041e\u041e\u041e \u00ab\u0420\u0435\u0434 \u0421\u043e\u0444\u0442\u00bb \u0420\u0415\u0414 \u041e\u0421 8.0  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u21163751), \u0410\u041e \u00ab\u0421\u0431\u0435\u0440\u0422\u0435\u0445\u00bb Platform V SberLinux OS Server 9.2.0-fstec  (\u0437\u0430\u043f\u0438\u0441\u044c \u0432 \u0435\u0434\u0438\u043d\u043e\u043c \u0440\u0435\u0435\u0441\u0442\u0440\u0435 \u0440\u043e\u0441\u0441\u0438\u0439\u0441\u043a\u0438\u0445 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c \u211618785)",
  "\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 \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 NFSv4 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 close \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": "\u0417\u0430\u0432\u0438\u0441\u0430\u043d\u0438\u0435 (CWE-833)",
  "\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 \u043a\u043e\u043c\u043f\u043e\u043d\u0435\u043d\u0442\u0430 NFSv4 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 close \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 \u0432\u0437\u0430\u0438\u043c\u043d\u043e\u0439 \u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u043a\u043e\u0439 \u043f\u043e\u0442\u043e\u043a\u043e\u0432 \u0432\u044b\u043f\u043e\u043b\u043d\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, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \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": "\u0418\u0441\u0447\u0435\u0440\u043f\u0430\u043d\u0438\u0435 \u0440\u0435\u0441\u0443\u0440\u0441\u043e\u0432",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://vuldb.com/ru/?id.302632\nhttps://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871\t\nhttps://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38\t\nhttps://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0\t\nhttps://lore.kernel.org/linux-cve-announce/2025040133-CVE-2025-21900-8d31@gregkh/\nhttps://access.redhat.com/security/cve/cve-2025-21900\nhttps://ubuntu.com/security/CVE-2025-21900\n\nhttps://wiki.astralinux.ru/astra-linux-se18-bulletin-2025-0811SE18\nhttp://repo.red-soft.ru/redos/8.0/x86_64/updates/\n\n",
  "\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-833",
  "\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": "\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 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 4,3)\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 4,8)"
}

CVE-2025-21900 (GCVE-0-2025-21900)

Vulnerability from cvelistv5 – Published: 2025-04-01 15:26 – Updated: 2026-08-05 11:55

Title

NFSv4: Fix a deadlock when recovering state on a sillyrenamed file

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix a deadlock when recovering state on a sillyrenamed file If the file is sillyrenamed, and slated for delete on close, it is possible for a server reboot to triggeer an open reclaim, with can again race with the application call to close(). When that happens, the call to put_nfs_open_context() can trigger a synchronous delegreturn call which deadlocks because it is not marked as privileged. Instead, ensure that the call to nfs4_inode_return_delegation_on_close() catches the delegreturn, and schedules it asynchronously.

Severity

7.5 (High)


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

5.5 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-10-01 17:18 UTC

CWE

CWE-667 - Improper Locking

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/4fe4ae6c2e01d0288…
https://git.kernel.org/stable/c/f41a60bc43e7abbc6…
https://git.kernel.org/stable/c/8f8df955f078e1a02…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: adb4b42d19aea91826621a8d0bac94cf2c08f8bc , < 4fe4ae6c2e01d028856b73b6328b12b8945df871 (git) Affected: adb4b42d19aea91826621a8d0bac94cf2c08f8bc , < f41a60bc43e7abbc636fee78bed0d74c31e738b0 (git) Affected: adb4b42d19aea91826621a8d0bac94cf2c08f8bc , < 8f8df955f078e1a023ee55161935000a67651f38 (git)
Linux	Linux	Affected: 6.11 Unaffected: 0 , < 6.11 (semver) Unaffected: 6.12.18 , ≤ 6.12.* (semver) Unaffected: 6.13.6 , ≤ 6.13.* (semver) Unaffected: 6.14 , ≤ * (original_commit_for_fix)

Show details on NVD website

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 5.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2025-21900",
                "options": [
                  {
                    "Exploitation": "none"
                  },
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                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
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                "timestamp": "2025-10-01T17:18:02.848036Z",
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          }
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                "cweId": "CWE-667",
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        "providerMetadata": {
          "dateUpdated": "2025-10-01T17:18:05.662Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs/delegation.c",
            "fs/nfs/delegation.h",
            "fs/nfs/nfs4proc.c"
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          "versions": [
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            {
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              "status": "affected",
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              "versionType": "git"
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        {
          "defaultStatus": "affected",
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            "fs/nfs/delegation.h",
            "fs/nfs/nfs4proc.c"
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.11"
            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.18",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.6",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
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                  "versionStartIncluding": "6.11",
                  "vulnerable": true
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                {
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        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4: Fix a deadlock when recovering state on a sillyrenamed file\n\nIf the file is sillyrenamed, and slated for delete on close, it is\npossible for a server reboot to triggeer an open reclaim, with can again\nrace with the application call to close(). When that happens, the call\nto put_nfs_open_context() can trigger a synchronous delegreturn call\nwhich deadlocks because it is not marked as privileged.\n\nInstead, ensure that the call to nfs4_inode_return_delegation_on_close()\ncatches the delegreturn, and schedules it asynchronously."
        }
      ],
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            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - This is NFSv4 client code whose vulnerable path is entered only in response to remote server behaviour \u2014 a server reboot/session reset (NFS4ERR_STALE_CLIENTID, NFS4ERR_BAD_SESSION, lease expiry) drives the state manager into open reclaim, and the blocking DELEGRETURN is an RPC to that server. A malicious or compromised NFS server, or an on-path attacker on a typical AUTH_SYS mount, can force state recovery at will over the network.\nAC:L - This is not a tight instruction-level race: the state manager holds the open-context reference across a full OPEN reclaim round trip whose duration the server chooses, and it can be stretched further with NFS4ERR_DELAY/NFS4ERR_GRACE, so the attacker controls the window width and can force recovery repeatedly until the race lands. The other side \u2014 an open, unlinked (sillyrenamed) file being closed \u2014 is ubiquitous in normal workloads (tmpfile(), mkstemp+unlink, editors, build systems, mail spools).\nPR:N - The attacker is the remote NFS server (or an on-path attacker) and needs no credentials or account on the victim client; the mount is a pre-existing deployment condition. Even under a purely local framing this would only require an unprivileged user, so no elevated privilege is needed on any path.\nUI:N - No human action is required \u2014 the attacker forces state recovery, and the sillyrename/close side is satisfied by ordinary background filesystem activity already running on the client.\nS:U - The deadlock is confined to the NFS client kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:N - This is purely a lock/RPC-ordering deadlock with no memory corruption, out-of-bounds access, or uninitialized data exposure. No information is disclosed to the attacker.\nI:N - No attacker-controlled data modification occurs; nothing is written out of bounds and no state is corrupted in an attacker-directed way. The pending silly-delete simply never completes.\nA:H - The NFSv4 state manager kthread deadlocks permanently with the session slot table left in the draining state, so every subsequent NFSv4 RPC to that server blocks forever \u2014 all processes touching any mount from that nfs_client hang unkillably in D state, umount and clean shutdown wedge, and recovery requires a hard reboot. On NFS-root systems (diskless workstations, HPC nodes, thin clients, embedded controllers) this hangs the entire machine."
            }
          ]
        }
      ],
      "providerMetadata": {
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/4fe4ae6c2e01d028856b73b6328b12b8945df871"
        },
        {
          "url": "https://git.kernel.org/stable/c/f41a60bc43e7abbc636fee78bed0d74c31e738b0"
        },
        {
          "url": "https://git.kernel.org/stable/c/8f8df955f078e1a023ee55161935000a67651f38"
        }
      ],
      "title": "NFSv4: Fix a deadlock when recovering state on a sillyrenamed file",
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2025-21900",
    "datePublished": "2025-04-01T15:26:51.290Z",
    "dateReserved": "2024-12-29T08:45:45.783Z",
    "dateUpdated": "2026-08-05T11:55:15.442Z",
    "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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.