drm: bridge: dw_hdmi: fix connector access for scdc

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm: bridge: dw_hdmi: fix connector access for scdc Commit 5d844091f237 ("drm/scdc-helper: Pimp SCDC debugs") changed the scdc interface to pick up an i2c adapter from a connector instead. However, in the case of dw-hdmi, the wrong connector was being used to pass i2c adapter information, since dw-hdmi's embedded connector structure is only populated when the bridge attachment callback explicitly asks for it. drm-meson is handling connector creation, so this won't happen, leading to a NULL pointer dereference. Fix it by having scdc functions access dw-hdmi's current connector pointer instead, which is assigned during the bridge enablement stage. [narmstrong: moved Fixes tag before first S-o-b and added Reported-by tag]

References

• https://git.kernel.org/stable/c/552f79aa9e801ed4f74d6b3221af78042ba4f235
• https://git.kernel.org/stable/c/98703e4e061fb8715c7613cd227e32cdfd136b23