Re: [PATCH] bpf: core: Fix the call ins's offset s32 -> s16 truncation

[Song Liu]

On Fri, Jan 7, 2022 at 9:11 PM Yichun Zhang (agentzh)
<yichun@xxxxxxxxxxxxx> wrote:
>
> The BPF interpreter always truncates the BPF CALL instruction's 32-bit
> jump offset to 16-bit. Large BPF programs run by the interpreter often
> hit this issue and result in weird behaviors when jumping to the wrong
> destination instructions.
>
> The BPF JIT compiler does not have this bug.
>
> Fixes: 1ea47e01ad6ea ("bpf: add support for bpf_call to interpreter")
> Signed-off-by: Yichun Zhang (agentzh) <yichun@xxxxxxxxxxxxx>

Acked-by: Song Liu <songliubraving@xxxxxx>