Описание
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Creating a child cpuset where cpuset.mems is never set leads to a div/0 when a VMA mempolicy with MPOL_F_RELATIVE_NODES rebinds in response to a CPU hotplug event. Reproduction steps:
- Create a cgroup w/ cpuset controls (do not set cpuset.mems)
- Move the task into the child cpuset
- Create a VMA mempolicy for that task with MPOL_F_RELATIVE_NODES
- unplug and hotplug a cpu echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online
- mempolicy rebind does a div/0 in mpol_relative_nodemask on the
call to __nodes_fold()
The cpuset code passes (cs->mems_allowed) which is not guaranteed to have
nodes to the rebind routine. Use cs->effective_mems instead, which is
guaranteed to have a non-empty nodemask once we reach that code path.
[ david: add a comment, slightly rephrase description ]
A flaw was found in the Linux kernel's cgroup/cpuset component. A local user can exploit this by configuring a child cpuset without explicitly setting its memory nodes. When a CPU hotplug event occurs, a division-by-zero error is triggered during memory policy rebind, leading to a system crash. This vulnerability results in a Denial of Service (DoS).
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Creating a child cpuset where cpuset.mems is never set leads to a div/0 when a VMA mempolicy with MPOL_F_RELATIVE_NODES rebinds in response to a CPU hotplug event. Reproduction steps: 1) Create a cgroup w/ cpuset controls (do not set cpuset.mems) 2) Move the task into the child cpuset 3) Create a VMA mempolicy for that task with MPOL_F_RELATIVE_NODES 4) unplug and hotplug a cpu echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online 5) mempolicy rebind does a div/0 in mpol_relative_nodemask on the call to __nodes_fold() The cpuset code passes (cs->mems_allowed) which is not guaranteed to have nodes to the rebind routine. Use cs->effective_mems instead, which is guaranteed to have a non-empty nodemask once we reach that code path. [ david: add a comment, slightly rephrase description ]
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Creating a child cpuset where cpuset.mems is never set leads to a div/0 when a VMA mempolicy with MPOL_F_RELATIVE_NODES rebinds in response to a CPU hotplug event. Reproduction steps: 1) Create a cgroup w/ cpuset controls (do not set cpuset.mems) 2) Move the task into the child cpuset 3) Create a VMA mempolicy for that task with MPOL_F_RELATIVE_NODES 4) unplug and hotplug a cpu echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online 5) mempolicy rebind does a div/0 in mpol_relative_nodemask on the call to __nodes_fold() The cpuset code passes (cs->mems_allowed) which is not guaranteed to have nodes to the rebind routine. Use cs->effective_mems instead, which is guaranteed to have a non-empty nodemask once we reach that code path. [ david: add a comment, slightly rephrase description ]
In the Linux kernel, the following vulnerability has been resolved: c ...
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Creating a child cpuset where cpuset.mems is never set leads to a div/0 when a VMA mempolicy with MPOL_F_RELATIVE_NODES rebinds in response to a CPU hotplug event. Reproduction steps: 1) Create a cgroup w/ cpuset controls (do not set cpuset.mems) 2) Move the task into the child cpuset 3) Create a VMA mempolicy for that task with MPOL_F_RELATIVE_NODES 4) unplug and hotplug a cpu echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online 5) mempolicy rebind does a div/0 in mpol_relative_nodemask on the call to __nodes_fold() The cpuset code passes (cs->mems_allowed) which is not guaranteed to have nodes to the rebind routine. Use cs->effective_mems instead, which is guaranteed to have a non-empty nodemask once we reach that code path. [ david: add a comment, slightly rephrase description ]
EPSS
5.5 Medium
CVSS3