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[PATCH bpf-next v4 2/2] tools/bpf: add verifier tests for accesses to map

Paul Chaignon <paul.chaignon@...>
 

This patch adds new test cases for accesses to map values from map
helpers.

Signed-off-by: Paul Chaignon <paul.chaignon@...>
---
tools/testing/selftests/bpf/test_verifier.c | 266 ++++++++++++++++++++++++++++
1 file changed, 266 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 3e7718b1a9ae..165e9ddfa446 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -64,6 +64,7 @@ struct bpf_test {
struct bpf_insn insns[MAX_INSNS];
int fixup_map1[MAX_FIXUPS];
int fixup_map2[MAX_FIXUPS];
+ int fixup_map3[MAX_FIXUPS];
int fixup_prog[MAX_FIXUPS];
int fixup_map_in_map[MAX_FIXUPS];
const char *errstr;
@@ -88,6 +89,11 @@ struct test_val {
int foo[MAX_ENTRIES];
};

+struct other_val {
+ long long foo;
+ long long bar;
+};
+
static struct bpf_test tests[] = {
{
"add+sub+mul",
@@ -5593,6 +5599,257 @@ static struct bpf_test tests[] = {
.errstr = "R1 min value is negative",
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
+ {
+ "map lookup helper access to map",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 8 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map update helper access to map",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_IMM(BPF_REG_4, 0),
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_update_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 10 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map update helper access to map: wrong size",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_IMM(BPF_REG_4, 0),
+ BPF_MOV64_REG(BPF_REG_3, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_update_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map1 = { 3 },
+ .fixup_map3 = { 10 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=8 off=0 size=16",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const imm)",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2,
+ offsetof(struct other_val, bar)),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 9 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const imm): out-of-bound 1",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2,
+ sizeof(struct other_val) - 4),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 9 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=16 off=12 size=8",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const imm): out-of-bound 2",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 9 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=16 off=-4 size=8",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const reg)",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_3,
+ offsetof(struct other_val, bar)),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 10 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const reg): out-of-bound 1",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_3,
+ sizeof(struct other_val) - 4),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 10 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=16 off=12 size=8",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via const reg): out-of-bound 2",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_MOV64_IMM(BPF_REG_3, -4),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 10 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=16 off=-4 size=8",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via variable)",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_3,
+ offsetof(struct other_val, bar), 4),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 11 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via variable): no max check",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 10 },
+ .result = REJECT,
+ .errstr = "R2 unbounded memory access, make sure to bounds check any array access into a map",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
+ {
+ "map helper access to adjusted map (via variable): wrong max check",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_3,
+ offsetof(struct other_val, bar) + 1, 4),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map3 = { 3, 11 },
+ .result = REJECT,
+ .errstr = "invalid access to map value, value_size=16 off=9 size=8",
+ .prog_type = BPF_PROG_TYPE_TRACEPOINT,
+ },
{
"map element value is preserved across register spilling",
.insns = {
@@ -11533,6 +11790,7 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
{
int *fixup_map1 = test->fixup_map1;
int *fixup_map2 = test->fixup_map2;
+ int *fixup_map3 = test->fixup_map3;
int *fixup_prog = test->fixup_prog;
int *fixup_map_in_map = test->fixup_map_in_map;

@@ -11556,6 +11814,14 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog,
} while (*fixup_map2);
}

+ if (*fixup_map3) {
+ map_fds[1] = create_map(sizeof(struct other_val), 1);
+ do {
+ prog[*fixup_map3].imm = map_fds[1];
+ fixup_map3++;
+ } while (*fixup_map3);
+ }
+
if (*fixup_prog) {
map_fds[2] = create_prog_array();
do {
--
2.14.1