You don’t need a backdoor in the source code you chuck it in the installer or have it download via the package manager, hell chuck it in snap since its got proprietary code. Not saying that’s the case but there are many routes for installing a backdoor that aren’t so easy to detect
Pretty sure that once upon a time one or more 3 letter agencies asked Torvalds to install a backdoor for them and he told them to shove it.
Plus the code is open source, if there was a backdoor someone would notice it eventually.
You don’t need a backdoor in the source code you chuck it in the installer or have it download via the package manager, hell chuck it in snap since its got proprietary code. Not saying that’s the case but there are many routes for installing a backdoor that aren’t so easy to detect
Compile it yourself :)