Описание
In the Linux kernel, the following vulnerability has been resolved:
drm/fbdev-dma: Add shadow buffering for deferred I/O
DMA areas are not necessarily backed by struct page, so we cannot
rely on it for deferred I/O. Allocate a shadow buffer for drivers
that require deferred I/O and use it as framebuffer memory.
Fixes driver errors about being "Unable to handle kernel NULL pointer
dereference at virtual address" or "Unable to handle kernel paging
request at virtual address".
The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial
allocation, which creates the DMA-backed buffer object, and a tail
that sets up the fbdev data structures. There is a tail function for
direct memory mappings and a tail function for deferred I/O with
the shadow buffer.
It is no longer possible to use deferred I/O without shadow buffer.
It can be re-added if there exists a reliably test for usable struct
page in the allocated DMA-backed buffer object.
A flaw was found in the Linux kernel's Direct Rendering Manager (DRM) framebuffer DMA driver. In configurations using deferred input/output (I/O), Direct Memory Access (DMA) memory buffers are not reliably backed by physical memory page structures. A local user could trigger this flaw during display operations, resulting in a NULL pointer dereference that causes a system crash and Denial of Service (DoS).
Отчет
This vulnerability is rated as having Low severity because triggering it requires local access on systems operating hardware configurations that utilize deferred I/O with DRM fbdev DMA buffers, and the resultant impact is limited to a system crash (denial of service). The issue is absent from Red Hat Enterprise Linux 8 and 9 where the vulnerable implementation was not present. Typical enterprise server deployments do not rely on the specific display adapters and deferred framebuffer DMA modes necessary to expose this flaw.
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 | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
Показывать по
Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Add shadow buffering for deferred I/O DMA areas are not necessarily backed by struct page, so we cannot rely on it for deferred I/O. Allocate a shadow buffer for drivers that require deferred I/O and use it as framebuffer memory. Fixes driver errors about being "Unable to handle kernel NULL pointer dereference at virtual address" or "Unable to handle kernel paging request at virtual address". The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial allocation, which creates the DMA-backed buffer object, and a tail that sets up the fbdev data structures. There is a tail function for direct memory mappings and a tail function for deferred I/O with the shadow buffer. It is no longer possible to use deferred I/O without shadow buffer. It can be re-added if there exists a reliably test for usable struct page in the allocated DMA-backed buffer object.
In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Add shadow buffering for deferred I/O DMA areas are not necessarily backed by struct page, so we cannot rely on it for deferred I/O. Allocate a shadow buffer for drivers that require deferred I/O and use it as framebuffer memory. Fixes driver errors about being "Unable to handle kernel NULL pointer dereference at virtual address" or "Unable to handle kernel paging request at virtual address". The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial allocation, which creates the DMA-backed buffer object, and a tail that sets up the fbdev data structures. There is a tail function for direct memory mappings and a tail function for deferred I/O with the shadow buffer. It is no longer possible to use deferred I/O without shadow buffer. It can be re-added if there exists a reliably test for usable struct page in the allocated DMA-backed buffer object.
In the Linux kernel, the following vulnerability has been resolved: d ...
In the Linux kernel, the following vulnerability has been resolved: drm/fbdev-dma: Add shadow buffering for deferred I/O DMA areas are not necessarily backed by struct page, so we cannot rely on it for deferred I/O. Allocate a shadow buffer for drivers that require deferred I/O and use it as framebuffer memory. Fixes driver errors about being "Unable to handle kernel NULL pointer dereference at virtual address" or "Unable to handle kernel paging request at virtual address". The patch splits drm_fbdev_dma_driver_fbdev_probe() in an initial allocation, which creates the DMA-backed buffer object, and a tail that sets up the fbdev data structures. There is a tail function for direct memory mappings and a tail function for deferred I/O with the shadow buffer. It is no longer possible to use deferred I/O without shadow buffer. It can be re-added if there exists a reliably test for usable struct page in the allocated DMA-backed buffer object.
Уязвимость функций drm_fbdev_dma_helper_fb_dirty(), drm_fbdev_dma_driver_fbdev_probe_tail() и drm_fbdev_dma_driver_fbdev_probe() (drivers/gpu/drm/drm_fbdev_dma.c) ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
5.5 Medium
CVSS3