Описание
In the Linux kernel, the following vulnerability has been resolved:
Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"
Patch series "mm: Avoid possible overflows in dirty throttling".
Dirty throttling logic assumes dirty limits in page units fit into
32-bits. This patch series makes sure this is true (see patch 2/2 for
more details).
This patch (of 2):
This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.
The commit is broken in several ways. Firstly, the removed (u64) cast
from the multiplication will introduce a multiplication overflow on 32-bit
archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the
default settings with 4GB of RAM will trigger this). Secondly, the
div64_u64() is unnecessarily expensive on 32-bit archs. We have
div64_ul() in case we want to be safe & cheap. Thirdly, if dirty
thresholds are larger than 1<<32 pages, then dirty balancing is going to
blow up in many other spectacular ways anyway so trying to fix one
possible overflow is just moot.
A vulnerability was found in the wb_dirty_limits() function in the Linux kernel, where a removed (u64) cast in the dtc->wb_thresh * dtc->bg_thresh operation can result in multiplication overflow on 32-bit architectures. This issue could lead to memory corruption or performance issues.
Отчет
Red Hat rates this as Moderate severity with an Attack Complexity rating of High, given that an attacker needs to be able to create enough dirty data (data not yet written to disk) in memory to cause the multiplication overflow, something which is more likely to be effective on systems with just 4GB of RAM, and would require the attacker to have this information about a given system when targeting their attack for a higher likelihood of success.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2024:6567 | 11.09.2024 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2024:6567 | 11.09.2024 |
| Red Hat Enterprise Linux 9.2 Extended Update Support | kernel | Fixed | RHSA-2024:6267 | 04.09.2024 |
| Red Hat Enterprise Linux 9.2 Extended Update Support | kernel-rt | Fixed | RHSA-2024:6268 | 04.09.2024 |
Показывать по
Дополнительная информация
Статус:
EPSS
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so tryin...
In the Linux kernel, the following vulnerability has been resolved: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so trying t
In the Linux kernel, the following vulnerability has been resolved: R ...
In the Linux kernel, the following vulnerability has been resolved: Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again" Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so tryin...
EPSS
4.7 Medium
CVSS3