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Date:   Wed, 16 Mar 2022 21:59:59 -0700
From:   John Fastabend <john.fastabend@gmail.com>
To:     kkourt@kkourt.io, Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     dwarves@vger.kernel.org, bpf@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Kornilios Kourtis <kornilios@isovalent.com>
Message-ID: <6232c04f3c9d2_487f20860@john.notmuch>
In-Reply-To: <20220316132338.3226871-1-kkourt@kkourt.io>
References: <YjHjLkYBk/XfXSK0@tinh>
 <20220316132338.3226871-1-kkourt@kkourt.io>
Subject: RE: [PATCH 1/2] pahole: avoid segfault when parsing bogus file
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kkourt@ wrote:
> From: Kornilios Kourtis <kornilios@isovalent.com>
> 
> 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@gmail.com>