From: Toke Høiland-Jørgensen <toke@redhat.com> mainline inclusion from mainline-5.16-rc1 commit 03e601f48b2da6fb44d0f7b86957a8f6bacfb347 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- 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 (cherry picked from commit 03e601f48b2da6fb44d0f7b86957a8f6bacfb347) Signed-off-by: Wang Yufen <wangyufen@huawei.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 fa45f5643c9b..4d182a9313f8 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2992,6 +2992,12 @@ 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