Vulnerability-Lookup

BDU:2025-04433 (CVE-2021-47646)

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

Title

Уязвимость функции bfq_setup_merge() модуля block/bfq-iosched.c поддержки блочного уровня ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации

Summary

Уязвимость функции bfq_setup_merge() модуля block/bfq-iosched.c поддержки блочного уровня ядра операционной системы Linux связана с повторным использованием ранее освобожденной памяти. Эксплуатация уязвимости может позволить нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации

Severity

6.8 (Medium) CVSS 2.0


                      
                        AV:L/AC:L/Au:S/C:C/I:C/A:C

7.8 (High) CVSS 3.0


                      
                        CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Class

Code vulnerability

Status

Confirmed by the vendor

Exploitation

Data structure manipulation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-416 - Использование после освобождения

Aliases

CVE-2021-47646

References

18 references

URL
https://www.cve.org/CVERecord?id=CVE-2021-47646
https://git.kernel.org/stable/c/f990f0985eda59d4f29fc83fcf300c92b1225d39
https://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6
https://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871
https://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613
https://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c
https://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607
https://lore.kernel.org/linux-cve-announce/2025022648-CVE-2021-47646-d726@gregkh/
https://git.kernel.org/linus/15729ff8143f8135b03988a100a19e66d7cb7ecd
https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.238
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.189
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.110
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.33
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.19
https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.2
https://access.redhat.com/security/cve/cve-2021-47646
https://security-tracker.debian.org/tracker/CVE-2021-47646
https://ubuntu.com/security/CVE-2021-47646

Impacted products

4 products from 4 vendors

Vendors

Canonical Ltd., Сообщество свободного программного обеспечения, Red Hat, Inc.

Products

Ubuntu, Debian GNU/Linux, Red Hat Enterprise Linux, Linux

Versions

20.04 LTS (Ubuntu), 11 (Debian GNU/Linux), 12 (Debian GNU/Linux), 22.04 LTS (Ubuntu), 9 (Red Hat Enterprise Linux), от 5.16 до 5.16.18 включительно (Linux), от 5.17 до 5.17.1 включительно (Linux), от 4.19.209 до 4.19.237 включительно (Linux), от 5.4.151 до 5.4.188 включительно (Linux), от 5.10.71 до 5.10.109 включительно (Linux), от 5.14.10 до 5.15.32 включительно (Linux)

Product types

Operating system

Platforms

Canonical Ltd. Ubuntu 20.04 LTS, Сообщество свободного программного обеспечения Debian GNU/Linux 11, Сообщество свободного программного обеспечения Debian GNU/Linux 12, Canonical Ltd. Ubuntu 22.04 LTS, Red Hat, Inc. Red Hat Enterprise Linux 9, Сообщество свободного программного обеспечения Linux от 5.16 до 5.16.18 включительно, Сообщество свободного программного обеспечения Linux от 5.17 до 5.17.1 включительно, Сообщество свободного программного обеспечения Linux от 4.19.209 до 4.19.237 включительно, Сообщество свободного программного обеспечения Linux от 5.4.151 до 5.4.188 включительно, Сообщество свободного программного обеспечения Linux от 5.10.71 до 5.10.109 включительно, Сообщество свободного программного обеспечения Linux от 5.14.10 до 5.15.32 включительно

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/f990f0985eda59d4f29fc83fcf300c92b1225d39 https://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6 https://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871 https://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613 https://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c https://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607 https://lore.kernel.org/linux-cve-announce/2025022648-CVE-2021-47646-d726@gregkh/ https://git.kernel.org/linus/15729ff8143f8135b03988a100a19e66d7cb7ecd https://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.238 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.189 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.110 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.33 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.19 https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.2 Для программных продуктов Red Hat Inc.: https://access.redhat.com/security/cve/cve-2021-47646 Для Debian GNU/Linux: https://security-tracker.debian.org/tracker/CVE-2021-47646 Для Ubuntu: https://ubuntu.com/security/CVE-2021-47646

JSON

To clipboard

{
  "CVSS 2.0": "AV:L/AC:L/Au:S/C:C/I:C/A:C",
  "CVSS 3.0": "AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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": "Canonical Ltd., \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, Red Hat, Inc.",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "20.04 LTS (Ubuntu), 11 (Debian GNU/Linux), 12 (Debian GNU/Linux), 22.04 LTS (Ubuntu), 9 (Red Hat Enterprise Linux), \u043e\u0442 5.16 \u0434\u043e 5.16.18 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.17 \u0434\u043e 5.17.1 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 4.19.209 \u0434\u043e 4.19.237 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.4.151 \u0434\u043e 5.4.188 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.10.71 \u0434\u043e 5.10.109 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e (Linux), \u043e\u0442 5.14.10 \u0434\u043e 5.15.32 \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://git.kernel.org/stable/c/f990f0985eda59d4f29fc83fcf300c92b1225d39\nhttps://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6\nhttps://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871\nhttps://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613\nhttps://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c\nhttps://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607\nhttps://lore.kernel.org/linux-cve-announce/2025022648-CVE-2021-47646-d726@gregkh/\nhttps://git.kernel.org/linus/15729ff8143f8135b03988a100a19e66d7cb7ecd\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.238\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.189\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.110\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.33\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.19\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.2\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-2021-47646\n\n\u0414\u043b\u044f Debian GNU/Linux:\nhttps://security-tracker.debian.org/tracker/CVE-2021-47646\n\n\u0414\u043b\u044f Ubuntu:\nhttps://ubuntu.com/security/CVE-2021-47646",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "08.03.2022",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "14.04.2025",
  "\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:2025-04433",
  "\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-2021-47646",
  "\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": "Ubuntu, Debian GNU/Linux, 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": "Canonical Ltd. Ubuntu 20.04 LTS , \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 Debian GNU/Linux 11 , \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 Debian GNU/Linux 12 , Canonical Ltd. Ubuntu 22.04 LTS , 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 5.16 \u0434\u043e 5.16.18 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \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 5.17 \u0434\u043e 5.17.1 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \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 4.19.209 \u0434\u043e 4.19.237 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \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 5.4.151 \u0434\u043e 5.4.188 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \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 5.10.71 \u0434\u043e 5.10.109 \u0432\u043a\u043b\u044e\u0447\u0438\u0442\u0435\u043b\u044c\u043d\u043e , \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 5.14.10 \u0434\u043e 5.15.32 \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 bfq_setup_merge() \u043c\u043e\u0434\u0443\u043b\u044f block/bfq-iosched.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0431\u043b\u043e\u0447\u043d\u043e\u0433\u043e \u0443\u0440\u043e\u0432\u043d\u044f \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 \u043e\u043a\u0430\u0437\u0430\u0442\u044c \u0432\u043e\u0437\u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0435 \u043d\u0430 \u043a\u043e\u043d\u0444\u0438\u0434\u0435\u043d\u0446\u0438\u0430\u043b\u044c\u043d\u043e\u0441\u0442\u044c, \u0446\u0435\u043b\u043e\u0441\u0442\u043d\u043e\u0441\u0442\u044c \u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u043d\u043e\u0441\u0442\u044c \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\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": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u043f\u043e\u0441\u043b\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0435\u043d\u0438\u044f (CWE-416)",
  "\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 bfq_setup_merge() \u043c\u043e\u0434\u0443\u043b\u044f block/bfq-iosched.c \u043f\u043e\u0434\u0434\u0435\u0440\u0436\u043a\u0438 \u0431\u043b\u043e\u0447\u043d\u043e\u0433\u043e \u0443\u0440\u043e\u0432\u043d\u044f \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 \u043f\u043e\u0432\u0442\u043e\u0440\u043d\u044b\u043c \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435\u043c \u0440\u0430\u043d\u0435\u0435 \u043e\u0441\u0432\u043e\u0431\u043e\u0436\u0434\u0435\u043d\u043d\u043e\u0439 \u043f\u0430\u043c\u044f\u0442\u0438. \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 \u043e\u043a\u0430\u0437\u0430\u0442\u044c \u0432\u043e\u0437\u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0435 \u043d\u0430 \u043a\u043e\u043d\u0444\u0438\u0434\u0435\u043d\u0446\u0438\u0430\u043b\u044c\u043d\u043e\u0441\u0442\u044c, \u0446\u0435\u043b\u043e\u0441\u0442\u043d\u043e\u0441\u0442\u044c \u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u043d\u043e\u0441\u0442\u044c \u0437\u0430\u0449\u0438\u0449\u0430\u0435\u043c\u043e\u0439 \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\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",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://www.cve.org/CVERecord?id=CVE-2021-47646\nhttps://git.kernel.org/stable/c/f990f0985eda59d4f29fc83fcf300c92b1225d39\nhttps://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6\nhttps://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871\nhttps://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613\nhttps://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c\nhttps://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607\nhttps://lore.kernel.org/linux-cve-announce/2025022648-CVE-2021-47646-d726@gregkh/\nhttps://git.kernel.org/linus/15729ff8143f8135b03988a100a19e66d7cb7ecd\nhttps://kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.238\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.189\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.110\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15.33\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.16.19\nhttps://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.2\nhttps://access.redhat.com/security/cve/cve-2021-47646\nhttps://security-tracker.debian.org/tracker/CVE-2021-47646\nhttps://ubuntu.com/security/CVE-2021-47646",
  "\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-416",
  "\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 6,8)\n\u0412\u044b\u0441\u043e\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 3.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 7,8)"
}

CVE-2021-47646 (GCVE-0-2021-47646)

Vulnerability from cvelistv5 – Published: 2025-02-26 01:54 – Updated: 2026-08-11 02:05

Title

Revert "Revert "block, bfq: honor already-setup queue merges""

Summary

In the Linux kernel, the following vulnerability has been resolved: Revert "Revert "block, bfq: honor already-setup queue merges"" A crash [1] happened to be triggered in conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq: honor already-setup queue merges""). Yet, the reverted commit was not the one introducing the bug. In fact, it actually triggered a UAF introduced by a different commit, and now fixed by commit d29bd41428cf ("block, bfq: reset last_bfqq_created on group change"). So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") out. This commit restores it. [1] https://bugzilla.kernel.org/show_bug.cgi?id=214503

Severity

7.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2025-02-27 17:59 UTC

CWE

CWE-416 - Use After Free

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/65d8a737452e88f25…
https://git.kernel.org/stable/c/abc2129e646af7b43…
https://git.kernel.org/stable/c/4083925bd6dc89216…
https://git.kernel.org/stable/c/15729ff8143f8135b…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 430a67f9d6169a7b3e328bceb2ef9542e4153c7c , < 65d8a737452e88f251fe5d925371de6d606df613 (git) Affected: 430a67f9d6169a7b3e328bceb2ef9542e4153c7c , < abc2129e646af7b43025d90a071f83043f1ae76c (git) Affected: 430a67f9d6169a7b3e328bceb2ef9542e4153c7c , < 4083925bd6dc89216d156474a8076feec904e607 (git) Affected: 430a67f9d6169a7b3e328bceb2ef9542e4153c7c , < 15729ff8143f8135b03988a100a19e66d7cb7ecd (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 5.15.33 , ≤ 5.15.* (semver) Unaffected: 5.16.19 , ≤ 5.16.* (semver) Unaffected: 5.17.2 , ≤ 5.17.* (semver) Unaffected: 5.18 , ≤ * (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": 7.8,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2021-47646",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-02-27T17:59:39.194997Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-416",
                "description": "CWE-416 Use After Free",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-02-27T18:02:30.637Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "block/bfq-iosched.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "65d8a737452e88f251fe5d925371de6d606df613",
              "status": "affected",
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "versionType": "git"
            },
            {
              "lessThan": "abc2129e646af7b43025d90a071f83043f1ae76c",
              "status": "affected",
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "versionType": "git"
            },
            {
              "lessThan": "4083925bd6dc89216d156474a8076feec904e607",
              "status": "affected",
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "versionType": "git"
            },
            {
              "lessThan": "15729ff8143f8135b03988a100a19e66d7cb7ecd",
              "status": "affected",
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "block/bfq-iosched.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.33",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.16.*",
              "status": "unaffected",
              "version": "5.16.19",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.17.*",
              "status": "unaffected",
              "version": "5.17.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.33",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.16.19",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.17.2",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.18",
                  "versionStartIncluding": "5.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"Revert \"block, bfq: honor already-setup queue merges\"\"\n\nA crash [1] happened to be triggered in conjunction with commit\n2d52c58b9c9b (\"block, bfq: honor already-setup queue merges\"). The\nlatter was then reverted by commit ebc69e897e17 (\"Revert \"block, bfq:\nhonor already-setup queue merges\"\"). Yet, the reverted commit was not\nthe one introducing the bug. In fact, it actually triggered a UAF\nintroduced by a different commit, and now fixed by commit d29bd41428cf\n(\"block, bfq: reset last_bfqq_created on group change\").\n\nSo, there is no point in keeping commit 2d52c58b9c9b (\"block, bfq:\nhonor already-setup queue merges\") out. This commit restores it.\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503"
        }
      ],
      "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 vulnerability is in the BFQ block I/O scheduler and is reached via local syscalls that submit I/O (read/write/fsync/ioctl), through bfq_init_rq \u2192 bfq_get_queue / bfq_setup_cooperator; it is not reachable from network packet processing.\nAC:L - An unprivileged attacker can reliably drive the buggy path by spawning processes that issue concurrent I/O and by migrating between blkcgs so queues are created, merged, moved, and freed under attacker control; success does not depend on victim state beyond BFQ being the active scheduler.\nPR:L - Only an unprivileged local account is required to submit I/O on a BFQ-scheduled device; changing the elevator needs privileges, but BFQ (with group I/O scheduling) is a common/default deployment (e.g. Android), so the attacker need not already be root.\nUI:N - Exploitation requires no action by another user; the attacker triggers the bug solely through their own I/O and process/cgroup activity.\nS:U - Impact is confined to the local kernel\u0027s security authority (memory corruption / privilege escalation on the host); there is no VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:H - The issue is a use-after-free of bfq_queue objects (dangling last_bfqq_created / broken merge state), which per kernel CVSS guidance yields an arbitrary-read primitive via heap reuse of the freed object.\nI:H - The same UAF/memory-corruption condition enables heap spraying and arbitrary-write / control-flow hijacking in kernel context, so integrity impact is High.\nA:H - The bug causes kernel oops/BUG_ON and slab freelist corruption (demonstrated in bugzilla 214503 crashes in bfq_get_queue / bfq_do_early_stable_merge), so availability impact is High."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-11T02:05:32.009Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613"
        },
        {
          "url": "https://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c"
        },
        {
          "url": "https://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607"
        },
        {
          "url": "https://git.kernel.org/stable/c/15729ff8143f8135b03988a100a19e66d7cb7ecd"
        }
      ],
      "title": "Revert \"Revert \"block, bfq: honor already-setup queue merges\"\"",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47646",
    "datePublished": "2025-02-26T01:54:15.122Z",
    "dateReserved": "2025-02-26T01:48:21.520Z",
    "dateUpdated": "2026-08-11T02:05:32.009Z",
    "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.