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bpf: allow helpers access to map element values 

Enable helpers to directly access a map element value by passing a
register type PTR_TO_MAP_VALUE (or PTR_TO_MAP_VALUE_ADJ) to helper
arguments ARG_PTR_TO_STACK or ARG_PTR_TO_RAW_STACK.

This enables several use cases. For example, a typical tracing program
might want to capture pathnames passed to sys_open() with:

struct trace_data {
	char pathname[PATHLEN];
};

SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
	struct trace_data data;
	bpf_probe_read(data.pathname, sizeof(data.pathname), ctx->di);

	/* consume data.pathname, for example via
	 * bpf_trace_printk() or bpf_perf_event_output()
	 */
}

Such a program could easily hit the stack limit in case PATHLEN needs to
be large or more local variables need to exist, both of which are quite
common scenarios. Allowing direct helper access to map element values,
one could do:

struct bpf_map_def SEC("maps") scratch_map = {
	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
	.key_size = sizeof(u32),
	.value_size = sizeof(struct trace_data),
	.max_entries = 1,
};

SEC("kprobe/sys_open")
int bpf_sys_open(struct pt_regs *ctx)
{
	int id = 0;
	struct trace_data *p = bpf_map_lookup_elem(&scratch_map, &id);
	if (!p)
		return;
	bpf_probe_read(p->pathname, sizeof(p->pathname), ctx->di);

	/* consume p->pathname, for example via
	 * bpf_trace_printk() or bpf_perf_event_output()
	 */
}

And wouldn't risk exhausting the stack.

Code changes are loosely modeled after commit 6841de8b0d ("bpf: allow
helpers access the packet directly"). Unlike with PTR_TO_PACKET, these
changes just work with ARG_PTR_TO_STACK and ARG_PTR_TO_RAW_STACK (not
ARG_PTR_TO_MAP_KEY, ARG_PTR_TO_MAP_VALUE, ...): adding those would be
trivial, but since there is not currently a use case for that, it's
reasonable to limit the set of changes.

Also, add new tests to make sure accesses to map element values from
helpers never go out of boundary, even when adjusted.

Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gianluca Borello 2017-01-09 10:19:47 -08:00 committed by David S. Miller
parent dbcfe5f76d
commit 5722569bb9
2 changed files with 498 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
kernel/bpf/verifier.c
View File

@ -627,7 +627,7 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
{
struct bpf_map *map = env->cur_state.regs[regno].map_ptr;
if (off < 0 || off + size > map->value_size) {
if (off < 0 || size <= 0 || off + size > map->value_size) {
verbose("invalid access to map value, value_size=%d off=%d size=%d\n",
map->value_size, off, size);
return -EACCES;
@ -1025,7 +1025,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
*/
if (type == CONST_IMM && reg->imm == 0)
/* final test in check_stack_boundary() */;
else if (type != PTR_TO_PACKET && type != expected_type)
else if (type != PTR_TO_PACKET && type != PTR_TO_MAP_VALUE &&
type != PTR_TO_MAP_VALUE_ADJ && type != expected_type)
goto err_type;
meta->raw_mode = arg_type == ARG_PTR_TO_RAW_STACK;
} else {
@ -1088,6 +1089,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
}
if (regs[regno - 1].type == PTR_TO_PACKET)
err = check_packet_access(env, regno - 1, 0, reg->imm);
else if (regs[regno - 1].type == PTR_TO_MAP_VALUE)
err = check_map_access(env, regno - 1, 0, reg->imm);
else if (regs[regno - 1].type == PTR_TO_MAP_VALUE_ADJ)
err = check_map_access_adj(env, regno - 1, 0, reg->imm);
else
err = check_stack_boundary(env, regno - 1, reg->imm,
zero_size_allowed, meta);

491
tools/testing/selftests/bpf/test_verifier.c
View File

@ -2905,6 +2905,497 @@ static struct bpf_test tests[] = {
.result = REJECT,
.errstr = "invalid bpf_context access",
},
{
"helper access to map: full range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, sizeof(struct test_val)),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to map: partial range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to map: empty range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=0 size=0",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to map: out-of-bound range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, sizeof(struct test_val) + 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=0 size=56",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to map: negative range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, -8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=0 size=-8",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): full range",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): partial range",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2, 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): empty range",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is outside of the array range",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): out-of-bound range",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo) + 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=4 size=52",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): negative range (> adjustment)",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2, -8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=4 size=-8",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const imm): negative range (< adjustment)",
.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_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_2, -1),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is outside of the array range",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): full range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3,
offsetof(struct test_val, foo)),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): partial range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3,
offsetof(struct test_val, foo)),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): empty range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is outside of the array range",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): out-of-bound range",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3,
offsetof(struct test_val, foo)),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo) + 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=4 size=52",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): negative range (> adjustment)",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3,
offsetof(struct test_val, foo)),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, -8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=4 size=-8",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via const reg): negative range (< adjustment)",
.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_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3,
offsetof(struct test_val, foo)),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, -1),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is outside of the array range",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via variable): full range",
.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_1, 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 test_val, foo), 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo)),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via variable): partial range",
.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_1, 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 test_val, foo), 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, 8),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"helper access to adjusted map (via variable): empty range",
.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_1, 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 test_val, foo), 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is outside of the array range",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"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_1, BPF_REG_0),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "R1 min value is negative, either use unsigned index or do a if (index >=0) check",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"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_1, 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 test_val, foo), 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
BPF_MOV64_IMM(BPF_REG_2,
sizeof(struct test_val) -
offsetof(struct test_val, foo) + 1),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_EMIT_CALL(BPF_FUNC_probe_read),
BPF_EXIT_INSN(),
},
.fixup_map2 = { 3 },
.errstr = "invalid access to map value, value_size=48 off=4 size=45",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
};
static int probe_filter_length(const struct bpf_insn *fp)