Description

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.)

Classification

CVE ID: CVE-2024-58006

Affected Products

Vendor: Linux, Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.03% (probability of being exploited)

EPSS Percentile: 3.82% (scored less or equal to compared to others)

EPSS Date: 2025-03-27 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2024-58006
https://git.kernel.org/stable/c/b5cacfd067060c75088363ed3e19779078be2755
https://git.kernel.org/stable/c/3229c15d6267de8e704b4085df8a82a5af2d63eb
https://git.kernel.org/stable/c/3708acbd5f169ebafe1faa519cb28adc56295546

Timeline