From: Edward Cree <ecree@solarflare.com>
Date: Fri, 15 Sep 2017 14:37:38 +0100
Subject: bpf/verifier: reject BPF_ALU64|BPF_END
Patch-mainline: v4.14-rc1
Git-commit: e67b8a685c7c984e834e3181ef4619cd7025a136
References: bsc#1056787
Neither ___bpf_prog_run nor the JITs accept it.
Also adds a new test case.
Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
kernel/bpf/verifier.c | 3 ++-
tools/testing/selftests/bpf/test_verifier.c | 16 ++++++++++++++++
2 files changed, 18 insertions(+), 1 deletion(-)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2292,7 +2292,8 @@ static int check_alu_op(struct bpf_verif
}
} else {
if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||
- (insn->imm != 16 && insn->imm != 32 && insn->imm != 64)) {
+ (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||
+ BPF_CLASS(insn->code) == BPF_ALU64) {
verbose("BPF_END uses reserved fields\n");
return -EINVAL;
}
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -6629,6 +6629,22 @@ static struct bpf_test tests[] = {
.result = REJECT,
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
+ {
+ "invalid 64-bit BPF_END",
+ .insns = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ {
+ .code = BPF_ALU64 | BPF_END | BPF_TO_LE,
+ .dst_reg = BPF_REG_0,
+ .src_reg = 0,
+ .off = 0,
+ .imm = 32,
+ },
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "BPF_END uses reserved fields",
+ .result = REJECT,
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)