From 35a855509e6ee3442477c8ebc6827b5b5d32a7b5 Mon Sep 17 00:00:00 2001 From: Shung-Hsi Yu Date: Wed, 12 Oct 2022 10:23:52 +0800 Subject: [PATCH] libbpf: Deal with section with no data gracefully ELF section data pointer returned by libelf may be NULL (if section has SHT_NOBITS), so null check section data pointer before attempting to copy license and kversion section. Fixes: cb1e5e961991 ("bpf tools: Collect version and license from ELF sections") Signed-off-by: Shung-Hsi Yu Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221012022353.7350-3-shung-hsi.yu@suse.com --- tools/lib/bpf/libbpf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2e8ac13de6a04..29e9df0c232b4 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1408,6 +1408,10 @@ static int bpf_object__check_endianness(struct bpf_object *obj) static int bpf_object__init_license(struct bpf_object *obj, void *data, size_t size) { + if (!data) { + pr_warn("invalid license section in %s\n", obj->path); + return -LIBBPF_ERRNO__FORMAT; + } /* libbpf_strlcpy() only copies first N - 1 bytes, so size + 1 won't * go over allowed ELF data section buffer */ @@ -1421,7 +1425,7 @@ bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size) { __u32 kver; - if (size != sizeof(kver)) { + if (!data || size != sizeof(kver)) { pr_warn("invalid kver section in %s\n", obj->path); return -LIBBPF_ERRNO__FORMAT; } -- 2.30.2