RE: [PATCH 1/2] pahole: avoid segfault when parsing bogus file

From: John Fastabend
Date: Thu Mar 17 2022 - 01:20:23 EST


kkourt@ wrote:
> From: Kornilios Kourtis <kornilios@xxxxxxxxxxxxx>
>
> When trying to use btf encoding for an apparently problematic kernel
> file, pahole segfaults. As can be seen below [1], the problem is that we
> are trying to dereference a NULL decoder.
>
> Fix this by checking the return value of dwfl_getmodules which [2] whill
> return -1 on errors or an offset if one of the modules did not return
> DWARF_CB_OK. (In this specific case, it was __cus__load_debug_types that
> returned DWARF_CB_ABORT.)
>

[...]

> [2] https://sourceware.org/git/?p=elfutils.git;a=blob;f=libdwfl/libdwfl.h;h=f98f1d525d94bc7bcfc7c816890de5907ee4bd6d;hb=HEAD#l200

Thanks for the reference and fix.

Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>