Describe CVE-2021-46934.
What is CVE-2021-46934?
In the Linux kernel, the following vulnerability has been resolved:

i2c: validate user data in compat ioctl

Wrong user data may cause warning in i2c_transfer(), ex: zero msgs.
Userspace should not be able to trigger warnings, so this patch adds
validation checks for user data in compact ioctl to prevent reported
warnings.