[akira2501]

> or make assignments not be an expression,

Or just reverse the expression:

    0 == curent->uid

So that the bug case is an error:

    0 = current->uid

[layer8]

Yes, that is well known, but it doesn’t prevent the issue in TFA.

[akira2501]

How does it not? Applied literally to the article, it would have turned this backdoor into a compile time error.

[umanwizard]

Because you can’t trust the person backdooring your code to help you out by writing in this style.

[akira2501]

Yes, they could literally violate the coding style, but presumably, that would draw more attention to what they've done, not less.