Описание
In the Linux kernel, the following vulnerability has been resolved:
PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers
Currently, the legacy I/O and memory sysfs handlers do not check
security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and
legacy_mem files unprotected when the kernel is locked down.
Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked
down") added the check to pci_write_config(), pci_mmap_resource(), and
pci_write_resource_io() to prevent userspace from programming DMA-capable
hardware that could be used to modify kernel code, but did not cover the
legacy handlers.
As a result, root can still write arbitrary I/O ports and map the legacy
I/O and memory spaces while the kernel is locked down, which is the same
capability the lockdown is meant to remove.
Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and
pci_mmap_legacy_io().
These generic handlers cover both architectures that define HAVE_PCI_LEGACY
(such as Alpha and PowerPC).
[bhelgaas: add Link]
A flaw was found in the Linux kernel's PCI/sysfs legacy I/O and memory handlers. These handlers failed to enforce kernel lockdown, a security mechanism designed to prevent privileged users from performing certain low-level operations. A local root user could exploit this by writing to arbitrary I/O ports and mapping legacy I/O and memory spaces, thereby bypassing the kernel lockdown. This bypass could allow the root user to perform actions that the lockdown feature is intended to restrict, potentially leading to a compromise of system integrity.
Отчет
This vulnerability is rated as Important because it enables a privileged local user to subvert kernel lockdown protections, which are relied upon to preserve host integrity under Secure Boot. On affected systems enforcing integrity or confidentiality lockdown modes, an administrative account could directly interact with legacy PCI memory and port I/O interfaces that omit lockdown validation. Consequently, an attacker possessing local root access can compromise kernel integrity and circumvent hardware-enforced boundaries.
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 | Under investigation | ||
| 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 | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Affected | ||
| Red Hat OpenShift Container Platform 5 | openshift/ose-rhel-coreos-9 | Affected |
Показывать по
Дополнительная информация
Статус:
EPSS
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers Currently, the legacy I/O and memory sysfs handlers do not check security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and legacy_mem files unprotected when the kernel is locked down. Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down") added the check to pci_write_config(), pci_mmap_resource(), and pci_write_resource_io() to prevent userspace from programming DMA-capable hardware that could be used to modify kernel code, but did not cover the legacy handlers. As a result, root can still write arbitrary I/O ports and map the legacy I/O and memory spaces while the kernel is locked down, which is the same capability the lockdown is meant to remove. Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and pci_mmap_legacy_io(). These generic handlers cover both architectures that define HAVE_PCI_LEGACY ...
In the Linux kernel, the following vulnerability has been resolved: PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers Currently, the legacy I/O and memory sysfs handlers do not check security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and legacy_mem files unprotected when the kernel is locked down. Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down") added the check to pci_write_config(), pci_mmap_resource(), and pci_write_resource_io() to prevent userspace from programming DMA-capable hardware that could be used to modify kernel code, but did not cover the legacy handlers. As a result, root can still write arbitrary I/O ports and map the legacy I/O and memory spaces while the kernel is locked down, which is the same capability the lockdown is meant to remove. Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and pci_mmap_legacy_io(). These generic handlers cover both architectures that define HAVE_PCI_LEGA
In the Linux kernel, the following vulnerability has been resolved: P ...
In the Linux kernel, the following vulnerability has been resolved: PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers Currently, the legacy I/O and memory sysfs handlers do not check security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and legacy_mem files unprotected when the kernel is locked down. Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down") added the check to pci_write_config(), pci_mmap_resource(), and pci_write_resource_io() to prevent userspace from programming DMA-capable hardware that could be used to modify kernel code, but did not cover the legacy handlers. As a result, root can still write arbitrary I/O ports and map the legacy I/O and memory spaces while the kernel is locked down, which is the same capability the lockdown is meant to remove. Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and pci_mmap_legacy_io(). These generic handlers cover both architectures that define HAVE_PCI_L...
EPSS
7 High
CVSS3