Files
linux/tools/testing/selftests/bpf/verifier/direct_value_access.c
Emil Tsalapatis 12a1fe6e12 bpf/verifier: Do not limit maximum direct offset into arena map
The verifier currently limits direct offsets into a map to 512MiB
to avoid overflow during pointer arithmetic. However, this prevents
arena maps from using direct addressing instructions to access data
at the end of > 512MiB arena maps. This is necessary when moving
arena globals to the end of the arena instead of the front.

Refactor the verifier code to remove the offset calculation during
direct value access calculations. This is possible because the only
two map types that implement .map_direct_value_addr() are arrays and
arenas, and they both do their own internal checks to ensure the
offset is within bounds.

Adjust selftests that expect the old error. These tests still fail
because the verifier identifies the access as out of bounds for the
map, so change them to expect an "invalid access to map value pointer"
error instead.

Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20251216173325.98465-3-emil@etsalapatis.com
2025-12-16 10:42:55 -08:00

351 lines
8.2 KiB
C

{
"direct map access, write test 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 8),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 8),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 40),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 5",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 32),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 8, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 6",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 40),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 4, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "R1 min value is outside of the allowed memory range",
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"direct map access, write test 7",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, -1),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 4, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer, value_size=48 off=4294967295",
},
{
"direct map access, write test 8",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 1),
BPF_ST_MEM(BPF_DW, BPF_REG_1, -1, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 9",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 48),
BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 4242),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer",
},
{
"direct map access, write test 10",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 47),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 11",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 48),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer",
},
{
"direct map access, write test 12",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, (1<<29)),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer, value_size=48 off=536870912",
},
{
"direct map access, write test 13",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, (1<<29)-1),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 4),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer, value_size=48 off=536870911",
},
{
"direct map access, write test 14",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 47),
BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1, 3 },
.result = ACCEPT,
.retval = 0xff,
},
{
"direct map access, write test 15",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1, 3 },
.result = ACCEPT,
.retval = 0xffff,
},
{
"direct map access, write test 16",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
BPF_LD_MAP_VALUE(BPF_REG_2, 0, 47),
BPF_ST_MEM(BPF_H, BPF_REG_2, 0, 0xffff),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1, 3 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=48 off=47 size=2",
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"direct map access, write test 17",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 46),
BPF_LD_MAP_VALUE(BPF_REG_2, 0, 46),
BPF_ST_MEM(BPF_H, BPF_REG_2, 1, 0xffff),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1, 3 },
.result = REJECT,
.errstr = "invalid access to map value, value_size=48 off=47 size=2",
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"direct map access, write test 18",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
BPF_ST_MEM(BPF_H, BPF_REG_1, 0, 42),
BPF_EXIT_INSN(),
},
.fixup_map_array_small = { 1 },
.result = REJECT,
.errstr = "R1 min value is outside of the allowed memory range",
},
{
"direct map access, write test 19",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 0),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42),
BPF_EXIT_INSN(),
},
.fixup_map_array_small = { 1 },
.result = ACCEPT,
.retval = 1,
},
{
"direct map access, write test 20",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_MAP_VALUE(BPF_REG_1, 0, 1),
BPF_ST_MEM(BPF_B, BPF_REG_1, 0, 42),
BPF_EXIT_INSN(),
},
.fixup_map_array_small = { 1 },
.result = REJECT,
.errstr = "invalid access to map value pointer",
},
{
"direct map access, invalid insn test 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0, 1, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid bpf_ld_imm64 insn",
},
{
"direct map access, invalid insn test 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 1, 0, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "BPF_LD_IMM64 uses reserved fields",
},
{
"direct map access, invalid insn test 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, ~0, 0, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "BPF_LD_IMM64 uses reserved fields",
},
{
"direct map access, invalid insn test 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, 0, ~0, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid bpf_ld_imm64 insn",
},
{
"direct map access, invalid insn test 5",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_VALUE, ~0, ~0, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid bpf_ld_imm64 insn",
},
{
"direct map access, invalid insn test 6",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, ~0, 0, 0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "BPF_LD_IMM64 uses reserved fields",
},
{
"direct map access, invalid insn test 7",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, ~0, 0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid bpf_ld_imm64 insn",
},
{
"direct map access, invalid insn test 8",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, ~0, ~0, 0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "invalid bpf_ld_imm64 insn",
},
{
"direct map access, invalid insn test 9",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_FD, 0, 0, 0, 47),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 1 },
.result = REJECT,
.errstr = "unrecognized bpf_ld_imm64 insn",
},