| ID |
CVE-2025-38427
|
| Sažetak |
In the Linux kernel, the following vulnerability has been resolved:
video: screen_info: Relocate framebuffers behind PCI bridges
Apply PCI host-bridge window offsets to screen_info framebuffers. Fixes
invalid access to I/O memory.
Resources behind a PCI host bridge can be relocated by a certain offset
in the kernel's CPU address range used for I/O. The framebuffer memory
range stored in screen_info refers to the CPU addresses as seen during
boot (where the offset is 0). During boot up, firmware may assign a
different memory offset to the PCI host bridge and thereby relocating
the framebuffer address of the PCI graphics device as seen by the kernel.
The information in screen_info must be updated as well.
The helper pcibios_bus_to_resource() performs the relocation of the
screen_info's framebuffer resource (given in PCI bus addresses). The
result matches the I/O-memory resource of the PCI graphics device (given
in CPU addresses). As before, we store away the information necessary to
later update the information in screen_info itself.
Commit 78aa89d1dfba ("firmware/sysfb: Update screen_info for relocated
EFI framebuffers") added the code for updating screen_info. It is based
on similar functionality that pre-existed in efifb. Efifb uses a pointer
to the PCI resource, while the newer code does a memcpy of the region.
Hence efifb sees any updates to the PCI resource and avoids the issue.
v3:
- Only use struct pci_bus_region for PCI bus addresses (Bjorn)
- Clarify address semantics in commit messages and comments (Bjorn)
v2:
- Fixed tags (Takashi, Ivan)
- Updated information on efifb |
| Reference |
|
| CVSS |
| Base: | 5.5 |
| Impact: | 3.6 |
| Exploitability: | 1.8 |
|
| Pristup |
| Vektor | Složenost | Autentikacija |
| LOCAL |
LOW |
LOW |
|
| Impact |
| Povjerljivost | Cjelovitost | Dostupnost |
| NONE |
NONE |
HIGH |
|
| CVSS vektor |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Zadnje važnije ažuriranje |
19-11-2025 - 18:59 |
| Objavljeno |
25-07-2025 - 15:15 |
