Re: [PATCH] libbpf: Fix integer overflow issue

[Al Viro]

On Tue, Oct 08, 2024 at 12:46:48AM +0800, I Hsin Cheng wrote:
> Fix integer overflow issue discovered by coverity scan, where
> "bpf_program_fd()" might return a value less than zero. Assignment of
> "prog_fd" to "kern_data" will result in integer overflow in that case.
> 
> Do a pre-check after the program fd is returned, if it's negative we
> should ignore this program and move on, or maybe add some error handling
> mechanism here.

We already had a mechanism there - the one you'd just disabled.
Namely, storing an unsigned long value with MSB set at given
offset.