From 4581e676d3be9d8c921a48bf18e92c5a8f31bf13 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 13 Dec 2021 17:00:32 -0800 Subject: libbpf: Fix potential uninit memory read In case of BPF_CORE_TYPE_ID_LOCAL we fill out target result explicitly. But targ_res itself isn't initialized in such a case, and subsequent call to bpf_core_patch_insn() might read uninitialized field (like fail_memsz_adjust in this case). So ensure that targ_res is zero-initialized for BPF_CORE_TYPE_ID_LOCAL case. This was reported by Coverity static analyzer. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211214010032.3843804-1-andrii@kernel.org --- tools/lib/bpf/relo_core.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/lib') diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index c770483b4c36..910865e29edc 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -1223,6 +1223,7 @@ int bpf_core_apply_relo_insn(const char *prog_name, struct bpf_insn *insn, /* TYPE_ID_LOCAL relo is special and doesn't need candidate search */ if (relo->kind == BPF_CORE_TYPE_ID_LOCAL) { /* bpf_insn's imm value could get out of sync during linking */ + memset(&targ_res, 0, sizeof(targ_res)); targ_res.validate = false; targ_res.poison = false; targ_res.orig_val = local_spec->root_type_id; -- cgit v1.2.3