CVE-2022-50412: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50412 is a vulnerability in the Linux kernel affecting the DRM bridge ADV7511 component. The issue was discovered in the CEC adapter unregistration process where the adapter operations are assumed to be callable after unregistering the CEC adapter (NVD).

The vulnerability occurs when unregistering the CEC I2C device after the CEC adapter. The cecunregisteradapter() function assumes that the underlying adapter operations are still callable, which can lead to a kernel oops when attempting to access invalid memory addresses. This happens specifically when the CEC adapter has a valid physical address during the unregistration procedure, as it attempts to invalidate the address by setting it to f.f.f.f (NVD).

When exploited, this vulnerability can cause a kernel oops, resulting in system instability. The specific impact includes the inability to handle kernel execution of user memory at virtual address 0000000000000000, leading to an internal error: Oops: 86000004 [#1] PREEMPT_RT SMP (NVD).

The fix involves modifying the unregistration sequence to ensure the i2c_cec is unregistered before the CEC adapter, and properly disabling the CEC clock afterwards. This prevents the invalid memory access scenario during the unregistration process (NVD).