From: Andrii Nakryiko Date: Wed, 3 Nov 2021 17:32:11 +0000 (-0700) Subject: libbpf: Validate that .BTF and .BTF.ext sections contain data X-Git-Tag: v6.6.17~8491^2~445^2~19^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=62554d52e71797eefa3fc15b54008038837bb2d4;p=platform%2Fkernel%2Flinux-rpi.git libbpf: Validate that .BTF and .BTF.ext sections contain data .BTF and .BTF.ext ELF sections should have SHT_PROGBITS type and contain data. If they are not, ELF is invalid or corrupted, so bail out. Otherwise this can lead to data->d_buf being NULL and SIGSEGV later on. Reported by oss-fuzz project. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20211103173213.1376990-4-andrii@kernel.org --- diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f836a19..0dc6465 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -3270,8 +3270,12 @@ static int bpf_object__elf_collect(struct bpf_object *obj) } else if (strcmp(name, MAPS_ELF_SEC) == 0) { obj->efile.btf_maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { + if (sh->sh_type != SHT_PROGBITS) + return -LIBBPF_ERRNO__FORMAT; btf_data = data; } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) { + if (sh->sh_type != SHT_PROGBITS) + return -LIBBPF_ERRNO__FORMAT; btf_ext_data = data; } else if (sh->sh_type == SHT_SYMTAB) { /* already processed during the first pass above */