On Wed, Sep 1, 2021 at 4:48 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote:
>
> If libbpf encounters an ELF file that has been stripped of its symbol
> table, it will crash in bpf_object__add_programs() when trying to
> dereference the obj->efile.symbols pointer.
>
> Fix this by erroring out of bpf_object__elf_collect() if it is not able
> able to find the symbol table.
>
> v2:
> - Move check into bpf_object__elf_collect() and add nice error message
>
> Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
Applied to bpf-next, thanks.
> tools/lib/bpf/libbpf.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 6f5e2757bb3c..997060182cef 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -2990,6 +2990,12 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
> }
> }
>
> + if (!obj->efile.symbols) {
> + pr_warn("elf: couldn't find symbol table in %s - stripped object file?\n",
> + obj->path);
> + return -ENOENT;
> + }
> +
> scn = NULL;
> while ((scn = elf_nextscn(elf, scn)) != NULL) {
> idx++;
> --
> 2.33.0
>
