Описание
In the Linux kernel, the following vulnerability has been resolved:
PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar()
In commit 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update
inbound map address") set_bar() was modified to support dynamically
changing the backing physical address of a BAR that was already configured.
This means that set_bar() can be called twice, without ever calling
clear_bar() (as calling clear_bar() would clear the BAR's PCI address
assigned by the host).
This can only be done if the new BAR size/flags does not differ from the
existing BAR configuration. Add these missing checks.
If we allow set_bar() to set e.g. a new BAR size that differs from the
existing BAR size, the new address translation range will be smaller than
the BAR size already determined by the host, which would mean that a read
past the new BAR size would pass the iATU untranslated, which could allow
the host to read memory not belonging to the new struct pci_epf_bar.
While at it, add comments which clarifies the support for dynamically
changing the physical address of a BAR. (Which was also missing.)
A flaw was found in the Linux kernel's Peripheral Component Interconnect Express (PCIe) DesignWare endpoint driver. When dynamically reconfiguring a Base Address Register (BAR), the driver fails to verify that the new BAR size and flags match the existing configuration. If a smaller size is configured, memory read requests from the connected host device can bypass address translation, allowing the host to read unauthorized system memory.
Отчет
Red Hat has evaluated this vulnerability as having a Moderate severity because it specifically impacts systems configured to run as PCIe endpoints using Synopsys DesignWare controllers, rather than standard host systems. Exploitation requires the kernel to operate in PCIe endpoint mode with dynamic Base Address Register reconfiguration enabled, which is not used in typical enterprise installations. Consequently, standard server and cloud deployments are unaffected, and exposure is primarily restricted to specialized embedded or automotive 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 | ||
| Red Hat Enterprise Linux 10 | kernel | Fixed | RHSA-2025:20095 | 11.11.2025 |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar() In commit 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address") set_bar() was modified to support dynamically changing the backing physical address of a BAR that was already configured. This means that set_bar() can be called twice, without ever calling clear_bar() (as calling clear_bar() would clear the BAR's PCI address assigned by the host). This can only be done if the new BAR size/flags does not differ from the existing BAR configuration. Add these missing checks. If we allow set_bar() to set e.g. a new BAR size that differs from the existing BAR size, the new address translation range will be smaller than the BAR size already determined by the host, which would mean that a read past the new BAR size would pass the iATU untranslated, which could allow the host to read memory not belonging to the new struct pci_e...
In the Linux kernel, the following vulnerability has been resolved: PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar() In commit 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address") set_bar() was modified to support dynamically changing the backing physical address of a BAR that was already configured. This means that set_bar() can be called twice, without ever calling clear_bar() (as calling clear_bar() would clear the BAR's PCI address assigned by the host). This can only be done if the new BAR size/flags does not differ from the existing BAR configuration. Add these missing checks. If we allow set_bar() to set e.g. a new BAR size that differs from the existing BAR size, the new address translation range will be smaller than the BAR size already determined by the host, which would mean that a read past the new BAR size would pass the iATU untranslated, which could allow the host to read memory not belonging to the new struct pci
PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar()
In the Linux kernel, the following vulnerability has been resolved: P ...
In the Linux kernel, the following vulnerability has been resolved: PCI: dwc: ep: Prevent changing BAR size/flags in pci_epc_set_bar() In commit 4284c88fff0e ("PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address") set_bar() was modified to support dynamically changing the backing physical address of a BAR that was already configured. This means that set_bar() can be called twice, without ever calling clear_bar() (as calling clear_bar() would clear the BAR's PCI address assigned by the host). This can only be done if the new BAR size/flags does not differ from the existing BAR configuration. Add these missing checks. If we allow set_bar() to set e.g. a new BAR size that differs from the existing BAR size, the new address translation range will be smaller than the BAR size already determined by the host, which would mean that a read past the new BAR size would pass the iATU untranslated, which could allow the host to read memory not belonging to the new struct ...
EPSS
5.5 Medium
CVSS3