🛡️ CVE-2023-54145 — kernel

bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log

In the Linux kernel, the following vulnerability has been resolved:

bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log

It's trivial for user to trigger "verifier log line truncated" warning,

as verifier has a fixed-sized buffer of 1024 bytes (as of now), and there are at

least two pieces of user-provided information that can be output through

this buffer, and both can be arbitrarily sized by user:

• BTF names;
• BTF.ext source code lines strings.

Verifier log buffer should be properly sized for typical verifier state

output. But it's sort-of expected that this buffer won't be long enough

in some circumstances. So let's drop the check. In any case code will

work correctly, at worst truncating a part of a single line output.