[CVE-2022-3606] libbpf: Fix null-pointer dereference in find_prog_by_sec_insn()

https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=d0d382f95a9270dcf803539d6781d6bd67e3f5b2

Change-Id: I79a802dcc158434e1ac7eee72856ca270dcfd1f1

diff --git a/src/libbpf.c b/src/libbpf.c
index 2ca30cc..46af324 100644 (file)
--- a/src/libbpf.c
+++ b/src/libbpf.c
@@ -4088,6 +4088,9 @@ static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj,
        int l = 0, r = obj->nr_programs - 1, m;
        struct bpf_program *prog;
 
+       if (!obj->nr_programs)
+               return NULL;
+
        while (l < r) {
                m = l + (r - l + 1) / 2;
                prog = &obj->programs[m];