From 1cbbcfbbd56efd994d643428c69467fe3c8ab672 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Sun, 6 Jan 2019 00:54:38 +0100
Subject: [PATCH] bpf: add various test cases for alu op on mixed dst register
types
Add couple of test_verifier tests to check sanitation of alu op insn
with pointer and scalar type coming from different paths. This also
includes BPF insns of the test reproducer provided by Jann Horn.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
tools/testing/selftests/bpf/test_verifier.c | 120 ++++++++++++++++++++
1 file changed, 120 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 10d44446e8013..2fd90d4568926 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -6933,6 +6933,126 @@ static struct bpf_test tests[] = {
.result = ACCEPT,
.retval = 1,
},
+ {
+ "map access: mixing value pointer and scalar, 1",
+ .insns = {
+ // load map value pointer into r0 and r2
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
+ BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ // load some number from the map into r1
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
+ // depending on r1, branch:
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 3),
+ // branch A
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ BPF_JMP_A(2),
+ // branch B
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_3, 0x100000),
+ // common instruction
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ // depending on r1, branch:
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+ // branch A
+ BPF_JMP_A(4),
+ // branch B
+ BPF_MOV64_IMM(BPF_REG_0, 0x13371337),
+ // verifier follows fall-through
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_2, 0x100000, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ // fake-dead code; targeted from branch A to
+ // prevent dead code sanitization
+ BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map_array_48b = { 1 },
+ .result = ACCEPT,
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "R2 tried to add from different pointers or scalars",
+ .retval = 0,
+ },
+ {
+ "map access: mixing value pointer and scalar, 2",
+ .insns = {
+ // load map value pointer into r0 and r2
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
+ BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ // load some number from the map into r1
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
+ // depending on r1, branch:
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
+ // branch A
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_3, 0x100000),
+ BPF_JMP_A(2),
+ // branch B
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ // common instruction
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ // depending on r1, branch:
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+ // branch A
+ BPF_JMP_A(4),
+ // branch B
+ BPF_MOV64_IMM(BPF_REG_0, 0x13371337),
+ // verifier follows fall-through
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_2, 0x100000, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ // fake-dead code; targeted from branch A to
+ // prevent dead code sanitization
+ BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map_array_48b = { 1 },
+ .result = ACCEPT,
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "R2 tried to add from different maps or paths",
+ .retval = 0,
+ },
+ {
+ "sanitation: alu with different scalars",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
+ BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
+ BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_3, 0x100000),
+ BPF_JMP_A(2),
+ BPF_MOV64_IMM(BPF_REG_2, 42),
+ BPF_MOV64_IMM(BPF_REG_3, 0x100001),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map_array_48b = { 1 },
+ .result = ACCEPT,
+ .retval = 0x100000,
+ },
{
"map access: value_ptr += known scalar, upper oob arith, test 1",
.insns = {
--
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