From 03e601f48b2da6fb44d0f7b86957a8f6bacfb347 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Wed, 1 Sep 2021 13:48:12 +0200 Subject: [PATCH] libbpf: Don't crash on object files with no symbol tables MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210901114812.204720-1-toke@redhat.com --- 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 88d8825fc6f6..8f579c6666b2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2993,6 +2993,12 @@ 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++; -- 2.20.1