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CVE-2021-47646

Опубликовано: 26 фев. 2025
Источник: redhat
CVSS3: 5.5

Описание

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

A flaw was found in the Linux kernel's Block Layer BFQ I/O scheduler. A Use-After-Free (UAF) vulnerability could be triggered by a specific commit related to queue merges. This flaw could lead to a system crash, resulting in a Denial of Service (DoS).

Отчет

This vulnerability is rated as Moderate because it requires local access to trigger, and successful exploitation results exclusively in a denial of service (system crash) without directly impacting data confidentiality or integrity. Under standard Red Hat Enterprise Linux configurations, BFQ is not the default I/O scheduler, significantly reducing exposure across typical deployments. Systems are only susceptible if the BFQ scheduler is explicitly configured for one or more block devices and subjected to concurrent queue operations.

Затронутые пакеты

ПлатформаПакетСостояниеРекомендацияРелиз
Red Hat Enterprise Linux 10kernelNot affected
Red Hat Enterprise Linux 6kernelNot affected
Red Hat Enterprise Linux 7kernelNot affected
Red Hat Enterprise Linux 7kernel-rtNot affected
Red Hat Enterprise Linux 8kernelOut of support scope
Red Hat Enterprise Linux 8kernel-rtOut of support scope
Red Hat Enterprise Linux 9kernel-rtAffected
Red Hat Enterprise Linux 9kernelFixedRHSA-2022:826715.11.2022
Red Hat Enterprise Linux 9kernelFixedRHSA-2022:826715.11.2022

Показывать по

Дополнительная информация

Статус:

Moderate
Дефект:
CWE-416
https://bugzilla.redhat.com/show_bug.cgi?id=2348285kernel: Revert "Revert "block, bfq: honor already-setup queue merges""

5.5 Medium

CVSS3

Связанные уязвимости

CVSS3: 7.8
ubuntu
больше 1 года назад

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

CVSS3: 7.8
nvd
больше 1 года назад

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

CVSS3: 7.8
debian
больше 1 года назад

In the Linux kernel, the following vulnerability has been resolved: R ...

CVSS3: 7.8
github
больше 1 года назад

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

CVSS3: 7.8
fstec
больше 4 лет назад

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

5.5 Medium

CVSS3