[PATCH AUTOSEL 5.16 008/217] libbpf: Detect corrupted ELF symbols section
From: Sasha Levin <sashal@kernel.org>
Date: 2022-01-18 02:20:16
Also in:
bpf, lkml, stable
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Andrii Nakryiko <andrii@kernel.org> [ Upstream commit 833907876be55205d0ec153dcd819c014404ee16 ] Prevent divide-by-zero if ELF is corrupted and has zero sh_entsize. Reported by oss-fuzz project. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <redacted> Link: https://lore.kernel.org/bpf/20211103173213.1376990-2-andrii@kernel.org (local) Signed-off-by: Sasha Levin <sashal@kernel.org> --- tools/lib/bpf/libbpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7c74342bb6680..b5bf1c074832e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -3555,7 +3555,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx); sh = elf_sec_hdr(obj, scn); - if (!sh) + if (!sh || sh->sh_entsize != sizeof(Elf64_Sym)) return -LIBBPF_ERRNO__FORMAT; dummy_var_btf_id = add_dummy_ksym_var(obj->btf);
--
2.34.1