Commit 4f8827d2 authored Apr 24, 2019 by Daniel Borkmann Committed by Alexei Starovoitov Apr 25, 2019

bpf, libbpf: fix segfault in bpf_object__init_maps' pr_debug statement



Ran into it while testing; in bpf_object__init_maps() data can be NULL
in the case where no map section is present. Therefore we simply cannot
access data->d_size before NULL test. Move the pr_debug() where it's
safe to access.

Fixes: d859900c ("bpf, libbpf: support global data/bss/rodata sections")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent 8837fe5d

tools/lib/bpf/libbpf.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -875,14 +875,14 @@ bpf_object__init_maps(struct bpf_object *obj, int flags)
		nr_maps++;
		}

		/* Alloc obj->maps and fill nr_maps. */
		pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
		nr_maps, data->d_size);
		if (!nr_maps && !nr_maps_glob)
		return 0;

		/* Assume equally sized map definitions */
		if (data) {
		pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
		nr_maps, data->d_size);

		map_def_sz = data->d_size / nr_maps;
		if (!data->d_size \|\| (data->d_size % nr_maps) != 0) {
		pr_warning("unable to determine map definition size "

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