Bug 2348034 (CVE-2022-49506)

Summary: CVE-2022-49506 kernel: drm/mediatek: Add vblank register/unregister callback functions
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:15:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/mediatek: Add vblank register/unregister callback functions

We encountered a kernel panic issue that callback data will be NULL when
it's using in ovl irq handler. There is a timing issue between
mtk_disp_ovl_irq_handler() and mtk_ovl_disable_vblank().

To resolve this issue, we use the flow to register/unregister vblank cb:
- Register callback function and callback data when crtc creates.
- Unregister callback function and callback data when crtc destroies.

With this solution, we can assure callback data will not be NULL when
vblank is disable.
Comment 1 Avinash Hanwate 2025-02-26 20:55:35 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022608-CVE-2022-49506-2808@gregkh/T