From 9683e5775c75097c46bd24e65411b16ac6c6cbb3 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 4 May 2021 16:49:10 -0700 Subject: [PATCH] libbpf: Add NULL check to add_dummy_ksym_var Avoids a segv if btf isn't present. Seen on the call path __bpf_object__open calling bpf_object__collect_externs. Fixes: 5bd022ec01f0 (libbpf: Support extern kernel function) Suggested-by: Stanislav Fomichev Suggested-by: Petar Penkov Signed-off-by: Ian Rogers Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210504234910.976501-1-irogers@google.com --- tools/lib/bpf/libbpf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e2a3cf437814..c41d9b2b59ac 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3216,6 +3216,9 @@ static int add_dummy_ksym_var(struct btf *btf) const struct btf_var_secinfo *vs; const struct btf_type *sec; + if (!btf) + return 0; + sec_btf_id = btf__find_by_name_kind(btf, KSYMS_SEC, BTF_KIND_DATASEC); if (sec_btf_id < 0) -- 2.20.1