From: Toke Høiland-Jørgensen toke@redhat.com
[ Upstream commit 03e601f48b2da6fb44d0f7b86957a8f6bacfb347 ]
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@redhat.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20210901114812.204720-1-toke@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 f1bc09e606cd1..994266b565c1a 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++;