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Merge branch 'verifier-fixes' 

Daniel Borkmann says:

====================
The series contains two fixes in BPF core and test cases. For details
please see individual patches. Thanks!
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
hifive-unleashed-5.1
Alexei Starovoitov 2018-10-31 16:53:18 -07:00
parent 3615353218 832c6f2c29
commit dfeb8f4c96
3 changed files with 305 additions and 40 deletions
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3
include/linux/bpf_verifier.h
View File

@ -51,6 +51,9 @@ struct bpf_reg_state {
* PTR_TO_MAP_VALUE_OR_NULL
*/
struct bpf_map *map_ptr;
/* Max size from any of the above. */
unsigned long raw;
};
/* Fixed part of pointer offset, pointer types only */
s32 off;

21
kernel/bpf/verifier.c
View File

@ -2852,10 +2852,6 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
regs[BPF_REG_0].type = NOT_INIT;
} else if (fn->ret_type == RET_PTR_TO_MAP_VALUE_OR_NULL ||
fn->ret_type == RET_PTR_TO_MAP_VALUE) {
if (fn->ret_type == RET_PTR_TO_MAP_VALUE)
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE;
else
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
/* There is no offset yet applied, variable or fixed */
mark_reg_known_zero(env, regs, BPF_REG_0);
/* remember map_ptr, so that check_map_access()
@ -2868,7 +2864,12 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return -EINVAL;
}
regs[BPF_REG_0].map_ptr = meta.map_ptr;
regs[BPF_REG_0].id = ++env->id_gen;
if (fn->ret_type == RET_PTR_TO_MAP_VALUE) {
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE;
} else {
regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
regs[BPF_REG_0].id = ++env->id_gen;
}
} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
int id = acquire_reference_state(env, insn_idx);
if (id < 0)
@ -3046,7 +3047,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
dst_reg->umax_value = umax_ptr;
dst_reg->var_off = ptr_reg->var_off;
dst_reg->off = ptr_reg->off + smin_val;
dst_reg->range = ptr_reg->range;
dst_reg->raw = ptr_reg->raw;
break;
}
/* A new variable offset is created. Note that off_reg->off
@ -3076,10 +3077,11 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
}
dst_reg->var_off = tnum_add(ptr_reg->var_off, off_reg->var_off);
dst_reg->off = ptr_reg->off;
dst_reg->raw = ptr_reg->raw;
if (reg_is_pkt_pointer(ptr_reg)) {
dst_reg->id = ++env->id_gen;
/* something was added to pkt_ptr, set range to zero */
dst_reg->range = 0;
dst_reg->raw = 0;
}
break;
case BPF_SUB:
@ -3108,7 +3110,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
dst_reg->var_off = ptr_reg->var_off;
dst_reg->id = ptr_reg->id;
dst_reg->off = ptr_reg->off - smin_val;
dst_reg->range = ptr_reg->range;
dst_reg->raw = ptr_reg->raw;
break;
}
/* A new variable offset is created. If the subtrahend is known
@ -3134,11 +3136,12 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
}
dst_reg->var_off = tnum_sub(ptr_reg->var_off, off_reg->var_off);
dst_reg->off = ptr_reg->off;
dst_reg->raw = ptr_reg->raw;
if (reg_is_pkt_pointer(ptr_reg)) {
dst_reg->id = ++env->id_gen;
/* something was added to pkt_ptr, set range to zero */
if (smin_val < 0)
dst_reg->range = 0;
dst_reg->raw = 0;
}
break;
case BPF_AND:

321
tools/testing/selftests/bpf/test_verifier.c
View File

@ -76,7 +76,7 @@ struct bpf_test {
int fixup_percpu_cgroup_storage[MAX_FIXUPS];
const char *errstr;
const char *errstr_unpriv;
uint32_t retval;
uint32_t retval, retval_unpriv;
enum {
UNDEF,
ACCEPT,
@ -3084,6 +3084,8 @@ static struct bpf_test tests[] = {
.fixup_prog1 = { 2 },
.result = ACCEPT,
.retval = 42,
/* Verifier rewrite for unpriv skips tail call here. */
.retval_unpriv = 2,
},
{
"stack pointer arithmetic",
@ -6454,6 +6456,256 @@ static struct bpf_test tests[] = {
.errstr = "R1 min value is negative",
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"map access: known scalar += value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_MOV64_IMM(BPF_REG_1, 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: value_ptr += known scalar",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_MOV64_IMM(BPF_REG_1, 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: unknown scalar += value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf),
BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: value_ptr += unknown scalar",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: value_ptr += value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R0 pointer += pointer prohibited",
},
{
"map access: known scalar -= value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_MOV64_IMM(BPF_REG_1, 4),
BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R1 tried to subtract pointer from scalar",
},
{
"map access: value_ptr -= known scalar",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_MOV64_IMM(BPF_REG_1, 4),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R0 min value is outside of the array range",
},
{
"map access: value_ptr -= known scalar, 2",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
BPF_MOV64_IMM(BPF_REG_1, 6),
BPF_MOV64_IMM(BPF_REG_2, 4),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_2),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: unknown scalar -= value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf),
BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R1 tried to subtract pointer from scalar",
},
{
"map access: value_ptr -= unknown scalar",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R0 min value is negative",
},
{
"map access: value_ptr -= unknown scalar, 2",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0xf),
BPF_ALU64_IMM(BPF_OR, BPF_REG_1, 0x7),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0x7),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = ACCEPT,
.retval = 1,
},
{
"map access: value_ptr -= value_ptr",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
BPF_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_0),
BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
},
.fixup_map_array_48b = { 3 },
.result = REJECT,
.errstr = "R0 invalid mem access 'inv'",
.errstr_unpriv = "R0 pointer -= pointer prohibited",
},
{
"map lookup helper access to map",
.insns = {
@ -13899,6 +14151,33 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_map_type prog_type,
}
}
static int set_admin(bool admin)
{
cap_t caps;
const cap_value_t cap_val = CAP_SYS_ADMIN;
int ret = -1;
caps = cap_get_proc();
if (!caps) {
perror("cap_get_proc");
return -1;
}
if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_val,
admin ? CAP_SET : CAP_CLEAR)) {
perror("cap_set_flag");
goto out;
}
if (cap_set_proc(caps)) {
perror("cap_set_proc");
goto out;
}
ret = 0;
out:
if (cap_free(caps))
perror("cap_free");
return ret;
}
static void do_test_single(struct bpf_test *test, bool unpriv,
int *passes, int *errors)
{
@ -13907,6 +14186,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
struct bpf_insn *prog = test->insns;
int map_fds[MAX_NR_MAPS];
const char *expected_err;
uint32_t expected_val;
uint32_t retval;
int i, err;
@ -13926,6 +14206,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
test->result_unpriv : test->result;
expected_err = unpriv && test->errstr_unpriv ?
test->errstr_unpriv : test->errstr;
expected_val = unpriv && test->retval_unpriv ?
test->retval_unpriv : test->retval;
reject_from_alignment = fd_prog < 0 &&
(test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS) &&
@ -13959,16 +14241,20 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
__u8 tmp[TEST_DATA_LEN << 2];
__u32 size_tmp = sizeof(tmp);
if (unpriv)
set_admin(true);
err = bpf_prog_test_run(fd_prog, 1, test->data,
sizeof(test->data), tmp, &size_tmp,
&retval, NULL);
if (unpriv)
set_admin(false);
if (err && errno != 524/*ENOTSUPP*/ && errno != EPERM) {
printf("Unexpected bpf_prog_test_run error\n");
goto fail_log;
}
if (!err && retval != test->retval &&
test->retval != POINTER_VALUE) {
printf("FAIL retval %d != %d\n", retval, test->retval);
if (!err && retval != expected_val &&
expected_val != POINTER_VALUE) {
printf("FAIL retval %d != %d\n", retval, expected_val);
goto fail_log;
}
}
@ -14011,33 +14297,6 @@ static bool is_admin(void)
return (sysadmin == CAP_SET);
}
static int set_admin(bool admin)
{
cap_t caps;
const cap_value_t cap_val = CAP_SYS_ADMIN;
int ret = -1;
caps = cap_get_proc();
if (!caps) {
perror("cap_get_proc");
return -1;
}
if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_val,
admin ? CAP_SET : CAP_CLEAR)) {
perror("cap_set_flag");
goto out;
}
if (cap_set_proc(caps)) {
perror("cap_set_proc");
goto out;
}
ret = 0;
out:
if (cap_free(caps))
perror("cap_free");
return ret;
}
static void get_unpriv_disabled()
{
char buf[2];