Описание
In the Linux kernel, the following vulnerability has been resolved:
vfio/type1: prevent underflow of locked_vm via exec()
When a vfio container is preserved across exec, the task does not change,
but it gets a new mm with locked_vm=0, and loses the count from existing
dma mappings. If the user later unmaps a dma mapping, locked_vm underflows
to a large unsigned value, and a subsequent dma map request fails with
ENOMEM in __account_locked_vm.
To avoid underflow, grab and save the mm at the time a dma is mapped.
Use that mm when adjusting locked_vm, rather than re-acquiring the saved
task's mm, which may have changed. If the saved mm is dead, do nothing.
locked_vm is incremented for existing mappings in a subsequent patch.
A flaw was found in the Linux kernel's vfio/type1 module. A local user could exploit this vulnerability when a vfio container is preserved across an exec() call. If the user unmaps a Direct Memory Access (DMA) mapping, the locked_vm counter can underflow. This underflow can cause subsequent DMA map requests to fail, leading to a Denial of Service (DoS) condition.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | ||
| 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:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: vfio/type1: prevent underflow of locked_vm via exec() When a vfio container is preserved across exec, the task does not change, but it gets a new mm with locked_vm=0, and loses the count from existing dma mappings. If the user later unmaps a dma mapping, locked_vm underflows to a large unsigned value, and a subsequent dma map request fails with ENOMEM in __account_locked_vm. To avoid underflow, grab and save the mm at the time a dma is mapped. Use that mm when adjusting locked_vm, rather than re-acquiring the saved task's mm, which may have changed. If the saved mm is dead, do nothing. locked_vm is incremented for existing mappings in a subsequent patch.
In the Linux kernel, the following vulnerability has been resolved: vfio/type1: prevent underflow of locked_vm via exec() When a vfio container is preserved across exec, the task does not change, but it gets a new mm with locked_vm=0, and loses the count from existing dma mappings. If the user later unmaps a dma mapping, locked_vm underflows to a large unsigned value, and a subsequent dma map request fails with ENOMEM in __account_locked_vm. To avoid underflow, grab and save the mm at the time a dma is mapped. Use that mm when adjusting locked_vm, rather than re-acquiring the saved task's mm, which may have changed. If the saved mm is dead, do nothing. locked_vm is incremented for existing mappings in a subsequent patch.
In the Linux kernel, the following vulnerability has been resolved: v ...
In the Linux kernel, the following vulnerability has been resolved: vfio/type1: prevent underflow of locked_vm via exec() When a vfio container is preserved across exec, the task does not change, but it gets a new mm with locked_vm=0, and loses the count from existing dma mappings. If the user later unmaps a dma mapping, locked_vm underflows to a large unsigned value, and a subsequent dma map request fails with ENOMEM in __account_locked_vm. To avoid underflow, grab and save the mm at the time a dma is mapped. Use that mm when adjusting locked_vm, rather than re-acquiring the saved task's mm, which may have changed. If the saved mm is dead, do nothing. locked_vm is incremented for existing mappings in a subsequent patch.
5.5 Medium
CVSS3