CVE-2024-46698

Summary

In the Linux kernel, the following vulnerability has been resolved:

video/aperture: optionally match the device in sysfb_disable()

In aperture_remove_conflicting_pci_devices(), we currently only call sysfb_disable() on vga class devices. This leads to the following problem when the pimary device is not VGA compatible:

1. A PCI device with a non-VGA class is the boot display
2. That device is probed first and it is not a VGA device so sysfb_disable() is not called, but the device resources are freed by aperture_detach_platform_device()
3. Non-primary GPU has a VGA class and it ends up calling sysfb_disable()
4. NULL pointer dereference via sysfb_disable() since the resources have already been freed by aperture_detach_platform_device() when it was called by the other device.

Fix this by passing a device pointer to sysfb_disable() and checking the device to determine if we should execute it or not.

v2: Fix build when CONFIG_SCREEN_INFO is not set v3: Move device check into the mutex Drop primary variable in aperture_remove_conflicting_pci_devices() Drop __init on pci sysfb_pci_dev_is_enabled()

Affected Software

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

References

• https://git.kernel.org/stable/c/17e78f43de0c6da34204cc858b4cc05671ea9acf
• https://git.kernel.org/stable/c/b49420d6a1aeb399e5b107fc6eb8584d0860fbd7

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