[PATCH bpf-next v5 4/8] bpftool: Check EVP_Digest when computing excl_prog_hash
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2026-07-07 19:31:11
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [tooling] (bpftool), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Quentin Monnet, Linus Torvalds
bpftool_prog_sign() ignores the return value of EVP_Digest(). If the
digest computation fails (context allocation failure, or a digest
fetch failure under OpenSSL), EVP_Digest() returns 0 and leaves the
output buffer untouched, but the function still reports success.
Fixes: 40863f4d6ef2 ("bpftool: Add support for signing BPF programs")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
tools/bpf/bpftool/sign.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/sign.c b/tools/bpf/bpftool/sign.c
index f9b742f4bb10..1257dba8ef2f 100644
--- a/tools/bpf/bpftool/sign.c
+++ b/tools/bpf/bpftool/sign.c@@ -175,8 +175,11 @@ int bpftool_prog_sign(struct bpf_load_and_run_opts *opts) goto cleanup; } - EVP_Digest(opts->insns, opts->insns_sz, opts->excl_prog_hash, - &opts->excl_prog_hash_sz, EVP_sha256(), NULL); + if (EVP_Digest(opts->insns, opts->insns_sz, opts->excl_prog_hash, + &opts->excl_prog_hash_sz, EVP_sha256(), NULL) != 1) { + err = -EIO; + goto cleanup; + } bd_out = BIO_new(BIO_s_mem()); if (!bd_out) {
--
2.43.0