Описание
In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Stop the active perfmon before being destroyed
Upon closing the file descriptor, the active performance monitor is not
stopped. Although all perfmons are destroyed in vc4_perfmon_close_file(),
the active performance monitor's pointer (vc4->active_perfmon) is still
retained.
If we open a new file descriptor and submit a few jobs with performance
monitors, the driver will attempt to stop the active performance monitor
using the stale pointer in vc4->active_perfmon. However, this pointer
is no longer valid because the previous process has already terminated,
and all performance monitors associated with it have been destroyed and
freed.
To fix this, when the active performance monitor belongs to a given
process, explicitly stop it before destroying and freeing it.
A flaw was found in the Linux kernel's Broadcom VideoCore (vc4) graphics driver. When a process closes its device file descriptor, an active performance monitor is not stopped before being destroyed, retaining a stale pointer in memory. A local user can trigger this use-after-free condition by submitting new graphics jobs, potentially leading to a system crash (denial of service) or privilege escalation.
Отчет
This vulnerability is rated as Moderate severity because it requires local user privileges to interact with the Direct Rendering Manager (DRM) subsystem, and successful exploitation is confined to systems with Broadcom VideoCore hardware. An attacker could leverage this use-after-free condition to trigger a kernel crash or potentially escalate privileges. Standard Red Hat Enterprise Linux releases do not enable the vc4 graphics driver, mitigating exposure in typical enterprise environments.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| 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 |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Stop the active perfmon before being destroyed Upon closing the file descriptor, the active performance monitor is not stopped. Although all perfmons are destroyed in `vc4_perfmon_close_file()`, the active performance monitor's pointer (`vc4->active_perfmon`) is still retained. If we open a new file descriptor and submit a few jobs with performance monitors, the driver will attempt to stop the active performance monitor using the stale pointer in `vc4->active_perfmon`. However, this pointer is no longer valid because the previous process has already terminated, and all performance monitors associated with it have been destroyed and freed. To fix this, when the active performance monitor belongs to a given process, explicitly stop it before destroying and freeing it.
In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Stop the active perfmon before being destroyed Upon closing the file descriptor, the active performance monitor is not stopped. Although all perfmons are destroyed in `vc4_perfmon_close_file()`, the active performance monitor's pointer (`vc4->active_perfmon`) is still retained. If we open a new file descriptor and submit a few jobs with performance monitors, the driver will attempt to stop the active performance monitor using the stale pointer in `vc4->active_perfmon`. However, this pointer is no longer valid because the previous process has already terminated, and all performance monitors associated with it have been destroyed and freed. To fix this, when the active performance monitor belongs to a given process, explicitly stop it before destroying and freeing it.
In the Linux kernel, the following vulnerability has been resolved: d ...
In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Stop the active perfmon before being destroyed Upon closing the file descriptor, the active performance monitor is not stopped. Although all perfmons are destroyed in `vc4_perfmon_close_file()`, the active performance monitor's pointer (`vc4->active_perfmon`) is still retained. If we open a new file descriptor and submit a few jobs with performance monitors, the driver will attempt to stop the active performance monitor using the stale pointer in `vc4->active_perfmon`. However, this pointer is no longer valid because the previous process has already terminated, and all performance monitors associated with it have been destroyed and freed. To fix this, when the active performance monitor belongs to a given process, explicitly stop it before destroying and freeing it.
5.5 Medium
CVSS3