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-rw-r--r--kernel/bpf/verifier.c618
1 files changed, 479 insertions, 139 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 09d5d972c9ff..7b05e8938d5c 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -176,7 +176,6 @@ struct bpf_verifier_stack_elem {
struct bpf_verifier_stack_elem *next;
};
-#define BPF_COMPLEXITY_LIMIT_INSNS 131072
#define BPF_COMPLEXITY_LIMIT_STACK 1024
#define BPF_COMPLEXITY_LIMIT_STATES 64
@@ -377,7 +376,8 @@ static bool is_release_function(enum bpf_func_id func_id)
static bool is_acquire_function(enum bpf_func_id func_id)
{
return func_id == BPF_FUNC_sk_lookup_tcp ||
- func_id == BPF_FUNC_sk_lookup_udp;
+ func_id == BPF_FUNC_sk_lookup_udp ||
+ func_id == BPF_FUNC_skc_lookup_tcp;
}
static bool is_ptr_cast_function(enum bpf_func_id func_id)
@@ -405,6 +405,7 @@ static const char * const reg_type_str[] = {
[PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null",
[PTR_TO_TCP_SOCK] = "tcp_sock",
[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
+ [PTR_TO_TP_BUFFER] = "tp_buffer",
};
static char slot_type_char[] = {
@@ -1091,7 +1092,7 @@ static int check_subprogs(struct bpf_verifier_env *env)
*/
subprog[env->subprog_cnt].start = insn_cnt;
- if (env->log.level > 1)
+ if (env->log.level & BPF_LOG_LEVEL2)
for (i = 0; i < env->subprog_cnt; i++)
verbose(env, "func#%d @%d\n", i, subprog[i].start);
@@ -1138,6 +1139,7 @@ static int mark_reg_read(struct bpf_verifier_env *env,
struct bpf_reg_state *parent)
{
bool writes = parent == state->parent; /* Observe write marks */
+ int cnt = 0;
while (parent) {
/* if read wasn't screened by an earlier write ... */
@@ -1149,12 +1151,25 @@ static int mark_reg_read(struct bpf_verifier_env *env,
parent->var_off.value, parent->off);
return -EFAULT;
}
+ if (parent->live & REG_LIVE_READ)
+ /* The parentage chain never changes and
+ * this parent was already marked as LIVE_READ.
+ * There is no need to keep walking the chain again and
+ * keep re-marking all parents as LIVE_READ.
+ * This case happens when the same register is read
+ * multiple times without writes into it in-between.
+ */
+ break;
/* ... then we depend on parent's value */
parent->live |= REG_LIVE_READ;
state = parent;
parent = state->parent;
writes = true;
+ cnt++;
}
+
+ if (env->longest_mark_read_walk < cnt)
+ env->longest_mark_read_walk = cnt;
return 0;
}
@@ -1163,30 +1178,32 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
{
struct bpf_verifier_state *vstate = env->cur_state;
struct bpf_func_state *state = vstate->frame[vstate->curframe];
- struct bpf_reg_state *regs = state->regs;
+ struct bpf_reg_state *reg, *regs = state->regs;
if (regno >= MAX_BPF_REG) {
verbose(env, "R%d is invalid\n", regno);
return -EINVAL;
}
+ reg = &regs[regno];
if (t == SRC_OP) {
/* check whether register used as source operand can be read */
- if (regs[regno].type == NOT_INIT) {
+ if (reg->type == NOT_INIT) {
verbose(env, "R%d !read_ok\n", regno);
return -EACCES;
}
/* We don't need to worry about FP liveness because it's read-only */
- if (regno != BPF_REG_FP)
- return mark_reg_read(env, &regs[regno],
- regs[regno].parent);
+ if (regno == BPF_REG_FP)
+ return 0;
+
+ return mark_reg_read(env, reg, reg->parent);
} else {
/* check whether register used as dest operand can be written to */
if (regno == BPF_REG_FP) {
verbose(env, "frame pointer is read only\n");
return -EACCES;
}
- regs[regno].live |= REG_LIVE_WRITTEN;
+ reg->live |= REG_LIVE_WRITTEN;
if (t == DST_OP)
mark_reg_unknown(env, regs, regno);
}
@@ -1412,7 +1429,7 @@ static int check_stack_access(struct bpf_verifier_env *env,
char tn_buf[48];
tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "variable stack access var_off=%s off=%d size=%d",
+ verbose(env, "variable stack access var_off=%s off=%d size=%d\n",
tn_buf, off, size);
return -EACCES;
}
@@ -1425,6 +1442,28 @@ static int check_stack_access(struct bpf_verifier_env *env,
return 0;
}
+static int check_map_access_type(struct bpf_verifier_env *env, u32 regno,
+ int off, int size, enum bpf_access_type type)
+{
+ struct bpf_reg_state *regs = cur_regs(env);
+ struct bpf_map *map = regs[regno].map_ptr;
+ u32 cap = bpf_map_flags_to_cap(map);
+
+ if (type == BPF_WRITE && !(cap & BPF_MAP_CAN_WRITE)) {
+ verbose(env, "write into map forbidden, value_size=%d off=%d size=%d\n",
+ map->value_size, off, size);
+ return -EACCES;
+ }
+
+ if (type == BPF_READ && !(cap & BPF_MAP_CAN_READ)) {
+ verbose(env, "read from map forbidden, value_size=%d off=%d size=%d\n",
+ map->value_size, off, size);
+ return -EACCES;
+ }
+
+ return 0;
+}
+
/* check read/write into map element returned by bpf_map_lookup_elem() */
static int __check_map_access(struct bpf_verifier_env *env, u32 regno, int off,
int size, bool zero_size_allowed)
@@ -1454,7 +1493,7 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
* need to try adding each of min_value and max_value to off
* to make sure our theoretical access will be safe.
*/
- if (env->log.level)
+ if (env->log.level & BPF_LOG_LEVEL)
print_verifier_state(env, state);
/* The minimum value is only important with signed
@@ -1955,6 +1994,32 @@ static int check_ctx_reg(struct bpf_verifier_env *env,
return 0;
}
+static int check_tp_buffer_access(struct bpf_verifier_env *env,
+ const struct bpf_reg_state *reg,
+ int regno, int off, int size)
+{
+ if (off < 0) {
+ verbose(env,
+ "R%d invalid tracepoint buffer access: off=%d, size=%d",
+ regno, off, size);
+ return -EACCES;
+ }
+ if (!tnum_is_const(reg->var_off) || reg->var_off.value) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env,
+ "R%d invalid variable buffer offset: off=%d, var_off=%s",
+ regno, off, tn_buf);
+ return -EACCES;
+ }
+ if (off + size > env->prog->aux->max_tp_access)
+ env->prog->aux->max_tp_access = off + size;
+
+ return 0;
+}
+
+
/* truncate register to smaller size (in bytes)
* must be called with size < BPF_REG_SIZE
*/
@@ -2011,7 +2076,9 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
verbose(env, "R%d leaks addr into map\n", value_regno);
return -EACCES;
}
-
+ err = check_map_access_type(env, regno, off, size, t);
+ if (err)
+ return err;
err = check_map_access(env, regno, off, size, false);
if (!err && t == BPF_READ && value_regno >= 0)
mark_reg_unknown(env, regs, value_regno);
@@ -2097,6 +2164,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
err = check_sock_access(env, insn_idx, regno, off, size, t);
if (!err && value_regno >= 0)
mark_reg_unknown(env, regs, value_regno);
+ } else if (reg->type == PTR_TO_TP_BUFFER) {
+ err = check_tp_buffer_access(env, reg, regno, off, size);
+ if (!err && t == BPF_READ && value_regno >= 0)
+ mark_reg_unknown(env, regs, value_regno);
} else {
verbose(env, "R%d invalid mem access '%s'\n", regno,
reg_type_str[reg->type]);
@@ -2157,6 +2228,29 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins
BPF_SIZE(insn->code), BPF_WRITE, -1, true);
}
+static int __check_stack_boundary(struct bpf_verifier_env *env, u32 regno,
+ int off, int access_size,
+ bool zero_size_allowed)
+{
+ struct bpf_reg_state *reg = reg_state(env, regno);
+
+ if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
+ access_size < 0 || (access_size == 0 && !zero_size_allowed)) {
+ if (tnum_is_const(reg->var_off)) {
+ verbose(env, "invalid stack type R%d off=%d access_size=%d\n",
+ regno, off, access_size);
+ } else {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env, "invalid stack type R%d var_off=%s access_size=%d\n",
+ regno, tn_buf, access_size);
+ }
+ return -EACCES;
+ }
+ return 0;
+}
+
/* when register 'regno' is passed into function that will read 'access_size'
* bytes from that pointer, make sure that it's within stack boundary
* and all elements of stack are initialized.
@@ -2169,7 +2263,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
{
struct bpf_reg_state *reg = reg_state(env, regno);
struct bpf_func_state *state = func(env, reg);
- int off, i, slot, spi;
+ int err, min_off, max_off, i, slot, spi;
if (reg->type != PTR_TO_STACK) {
/* Allow zero-byte read from NULL, regardless of pointer type */
@@ -2183,21 +2277,57 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
return -EACCES;
}
- /* Only allow fixed-offset stack reads */
- if (!tnum_is_const(reg->var_off)) {
- char tn_buf[48];
+ if (tnum_is_const(reg->var_off)) {
+ min_off = max_off = reg->var_off.value + reg->off;
+ err = __check_stack_boundary(env, regno, min_off, access_size,
+ zero_size_allowed);
+ if (err)
+ return err;
+ } else {
+ /* Variable offset is prohibited for unprivileged mode for
+ * simplicity since it requires corresponding support in
+ * Spectre masking for stack ALU.
+ * See also retrieve_ptr_limit().
+ */
+ if (!env->allow_ptr_leaks) {
+ char tn_buf[48];
- tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
- verbose(env, "invalid variable stack read R%d var_off=%s\n",
- regno, tn_buf);
- return -EACCES;
- }
- off = reg->off + reg->var_off.value;
- if (off >= 0 || off < -MAX_BPF_STACK || off + access_size > 0 ||
- access_size < 0 || (access_size == 0 && !zero_size_allowed)) {
- verbose(env, "invalid stack type R%d off=%d access_size=%d\n",
- regno, off, access_size);
- return -EACCES;
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env, "R%d indirect variable offset stack access prohibited for !root, var_off=%s\n",
+ regno, tn_buf);
+ return -EACCES;
+ }
+ /* Only initialized buffer on stack is allowed to be accessed
+ * with variable offset. With uninitialized buffer it's hard to
+ * guarantee that whole memory is marked as initialized on
+ * helper return since specific bounds are unknown what may
+ * cause uninitialized stack leaking.
+ */
+ if (meta && meta->raw_mode)
+ meta = NULL;
+
+ if (reg->smax_value >= BPF_MAX_VAR_OFF ||
+ reg->smax_value <= -BPF_MAX_VAR_OFF) {
+ verbose(env, "R%d unbounded indirect variable offset stack access\n",
+ regno);
+ return -EACCES;
+ }
+ min_off = reg->smin_value + reg->off;
+ max_off = reg->smax_value + reg->off;
+ err = __check_stack_boundary(env, regno, min_off, access_size,
+ zero_size_allowed);
+ if (err) {
+ verbose(env, "R%d min value is outside of stack bound\n",
+ regno);
+ return err;
+ }
+ err = __check_stack_boundary(env, regno, max_off, access_size,
+ zero_size_allowed);
+ if (err) {
+ verbose(env, "R%d max value is outside of stack bound\n",
+ regno);
+ return err;
+ }
}
if (meta && meta->raw_mode) {
@@ -2206,10 +2336,10 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
return 0;
}
- for (i = 0; i < access_size; i++) {
+ for (i = min_off; i < max_off + access_size; i++) {
u8 *stype;
- slot = -(off + i) - 1;
+ slot = -i - 1;
spi = slot / BPF_REG_SIZE;
if (state->allocated_stack <= slot)
goto err;
@@ -2222,8 +2352,16 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
goto mark;
}
err:
- verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
- off, i, access_size);
+ if (tnum_is_const(reg->var_off)) {
+ verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
+ min_off, i - min_off, access_size);
+ } else {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose(env, "invalid indirect read from stack var_off %s+%d size %d\n",
+ tn_buf, i - min_off, access_size);
+ }
return -EACCES;
mark:
/* reading any byte out of 8-byte 'spill_slot' will cause
@@ -2232,7 +2370,7 @@ mark:
mark_reg_read(env, &state->stack[spi].spilled_ptr,
state->stack[spi].spilled_ptr.parent);
}
- return update_stack_depth(env, state, off);
+ return update_stack_depth(env, state, min_off);
}
static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
@@ -2247,6 +2385,10 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno,
return check_packet_access(env, regno, reg->off, access_size,
zero_size_allowed);
case PTR_TO_MAP_VALUE:
+ if (check_map_access_type(env, regno, reg->off, access_size,
+ meta && meta->raw_mode ? BPF_WRITE :
+ BPF_READ))
+ return -EACCES;
return check_map_access(env, regno, reg->off, access_size,
zero_size_allowed);
default: /* scalar_value|ptr_to_stack or invalid ptr */
@@ -2353,6 +2495,22 @@ static bool arg_type_is_mem_size(enum bpf_arg_type type)
type == ARG_CONST_SIZE_OR_ZERO;
}
+static bool arg_type_is_int_ptr(enum bpf_arg_type type)
+{
+ return type == ARG_PTR_TO_INT ||
+ type == ARG_PTR_TO_LONG;
+}
+
+static int int_ptr_type_to_size(enum bpf_arg_type type)
+{
+ if (type == ARG_PTR_TO_INT)
+ return sizeof(u32);
+ else if (type == ARG_PTR_TO_LONG)
+ return sizeof(u64);
+
+ return -EINVAL;
+}
+
static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
enum bpf_arg_type arg_type,
struct bpf_call_arg_meta *meta)
@@ -2385,10 +2543,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
if (arg_type == ARG_PTR_TO_MAP_KEY ||
arg_type == ARG_PTR_TO_MAP_VALUE ||
- arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) {
+ arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE ||
+ arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL) {
expected_type = PTR_TO_STACK;
- if (!type_is_pkt_pointer(type) && type != PTR_TO_MAP_VALUE &&
- type != expected_type)
+ if (register_is_null(reg) &&
+ arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL)
+ /* final test in check_stack_boundary() */;
+ else if (!type_is_pkt_pointer(type) &&
+ type != PTR_TO_MAP_VALUE &&
+ type != expected_type)
goto err_type;
} else if (arg_type == ARG_CONST_SIZE ||
arg_type == ARG_CONST_SIZE_OR_ZERO) {
@@ -2420,6 +2583,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
}
meta->ref_obj_id = reg->ref_obj_id;
}
+ } else if (arg_type == ARG_PTR_TO_SOCKET) {
+ expected_type = PTR_TO_SOCKET;
+ if (type != expected_type)
+ goto err_type;
} else if (arg_type == ARG_PTR_TO_SPIN_LOCK) {
if (meta->func_id == BPF_FUNC_spin_lock) {
if (process_spin_lock(env, regno, true))
@@ -2445,6 +2612,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
type != expected_type)
goto err_type;
meta->raw_mode = arg_type == ARG_PTR_TO_UNINIT_MEM;
+ } else if (arg_type_is_int_ptr(arg_type)) {
+ expected_type = PTR_TO_STACK;
+ if (!type_is_pkt_pointer(type) &&
+ type != PTR_TO_MAP_VALUE &&
+ type != expected_type)
+ goto err_type;
} else {
verbose(env, "unsupported arg_type %d\n", arg_type);
return -EFAULT;
@@ -2471,6 +2644,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
meta->map_ptr->key_size, false,
NULL);
} else if (arg_type == ARG_PTR_TO_MAP_VALUE ||
+ (arg_type == ARG_PTR_TO_MAP_VALUE_OR_NULL &&
+ !register_is_null(reg)) ||
arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE) {
/* bpf_map_xxx(..., map_ptr, ..., value) call:
* check [value, value + map->value_size) validity
@@ -2526,6 +2701,13 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
err = check_helper_mem_access(env, regno - 1,
reg->umax_value,
zero_size_allowed, meta);
+ } else if (arg_type_is_int_ptr(arg_type)) {
+ int size = int_ptr_type_to_size(arg_type);
+
+ err = check_helper_mem_access(env, regno, size, false, meta);
+ if (err)
+ return err;
+ err = check_ptr_alignment(env, reg, 0, size, true);
}
return err;
@@ -2613,6 +2795,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
func_id != BPF_FUNC_map_push_elem)
goto error;
break;
+ case BPF_MAP_TYPE_SK_STORAGE:
+ if (func_id != BPF_FUNC_sk_storage_get &&
+ func_id != BPF_FUNC_sk_storage_delete)
+ goto error;
+ break;
default:
break;
}
@@ -2676,6 +2863,11 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
map->map_type != BPF_MAP_TYPE_STACK)
goto error;
break;
+ case BPF_FUNC_sk_storage_get:
+ case BPF_FUNC_sk_storage_delete:
+ if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
+ goto error;
+ break;
default:
break;
}
@@ -2905,7 +3097,7 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
/* and go analyze first insn of the callee */
*insn_idx = target_insn;
- if (env->log.level) {
+ if (env->log.level & BPF_LOG_LEVEL) {
verbose(env, "caller:\n");
print_verifier_state(env, caller);
verbose(env, "callee:\n");
@@ -2945,7 +3137,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
return err;
*insn_idx = callee->callsite + 1;
- if (env->log.level) {
+ if (env->log.level & BPF_LOG_LEVEL) {
verbose(env, "returning from callee:\n");
print_verifier_state(env, callee);
verbose(env, "to caller at %d:\n", *insn_idx);
@@ -2979,6 +3171,7 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
int func_id, int insn_idx)
{
struct bpf_insn_aux_data *aux = &env->insn_aux_data[insn_idx];
+ struct bpf_map *map = meta->map_ptr;
if (func_id != BPF_FUNC_tail_call &&
func_id != BPF_FUNC_map_lookup_elem &&
@@ -2989,11 +3182,24 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
func_id != BPF_FUNC_map_peek_elem)
return 0;
- if (meta->map_ptr == NULL) {
+ if (map == NULL) {
verbose(env, "kernel subsystem misconfigured verifier\n");
return -EINVAL;
}
+ /* In case of read-only, some additional restrictions
+ * need to be applied in order to prevent altering the
+ * state of the map from program side.
+ */
+ if ((map->map_flags & BPF_F_RDONLY_PROG) &&
+ (func_id == BPF_FUNC_map_delete_elem ||
+ func_id == BPF_FUNC_map_update_elem ||
+ func_id == BPF_FUNC_map_push_elem ||
+ func_id == BPF_FUNC_map_pop_elem)) {
+ verbose(env, "write into map forbidden\n");
+ return -EACCES;
+ }
+
if (!BPF_MAP_PTR(aux->map_state))
bpf_map_ptr_store(aux, meta->map_ptr,
meta->map_ptr->unpriv_array);
@@ -3157,19 +3363,11 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
- if (is_acquire_function(func_id)) {
- int id = acquire_reference_state(env, insn_idx);
-
- if (id < 0)
- return id;
- /* For mark_ptr_or_null_reg() */
- regs[BPF_REG_0].id = id;
- /* For release_reference() */
- regs[BPF_REG_0].ref_obj_id = id;
- } else {
- /* For mark_ptr_or_null_reg() */
- regs[BPF_REG_0].id = ++env->id_gen;
- }
+ regs[BPF_REG_0].id = ++env->id_gen;
+ } else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
+ mark_reg_known_zero(env, regs, BPF_REG_0);
+ regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
+ regs[BPF_REG_0].id = ++env->id_gen;
} else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
@@ -3180,9 +3378,19 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn
return -EINVAL;
}
- if (is_ptr_cast_function(func_id))
+ if (is_ptr_cast_function(func_id)) {
/* For release_reference() */
regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id;
+ } else if (is_acquire_function(func_id)) {
+ int id = acquire_reference_state(env, insn_idx);
+
+ if (id < 0)
+ return id;
+ /* For mark_ptr_or_null_reg() */
+ regs[BPF_REG_0].id = id;
+ /* For release_reference() */
+ regs[BPF_REG_0].ref_obj_id = id;
+ }
do_refine_retval_range(regs, fn->ret_type, func_id, &meta);
@@ -3282,6 +3490,9 @@ static int retrieve_ptr_limit(const struct bpf_reg_state *ptr_reg,
switch (ptr_reg->type) {
case PTR_TO_STACK:
+ /* Indirect variable offset stack access is prohibited in
+ * unprivileged mode so it's not handled here.
+ */
off = ptr_reg->off + ptr_reg->var_off.value;
if (mask_to_left)
*ptr_limit = MAX_BPF_STACK + off;
@@ -4982,23 +5193,17 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
insn->dst_reg);
return -EACCES;
}
- if (env->log.level)
+ if (env->log.level & BPF_LOG_LEVEL)
print_verifier_state(env, this_branch->frame[this_branch->curframe]);
return 0;
}
-/* return the map pointer stored inside BPF_LD_IMM64 instruction */
-static struct bpf_map *ld_imm64_to_map_ptr(struct bpf_insn *insn)
-{
- u64 imm64 = ((u64) (u32) insn[0].imm) | ((u64) (u32) insn[1].imm) << 32;
-
- return (struct bpf_map *) (unsigned long) imm64;
-}
-
/* verify BPF_LD_IMM64 instruction */
static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
+ struct bpf_insn_aux_data *aux = cur_aux(env);
struct bpf_reg_state *regs = cur_regs(env);
+ struct bpf_map *map;
int err;
if (BPF_SIZE(insn->code) != BPF_DW) {
@@ -5022,11 +5227,22 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn)
return 0;
}
- /* replace_map_fd_with_map_ptr() should have caught bad ld_imm64 */
- BUG_ON(insn->src_reg != BPF_PSEUDO_MAP_FD);
+ map = env->used_maps[aux->map_index];
+ mark_reg_known_zero(env, regs, insn->dst_reg);
+ regs[insn->dst_reg].map_ptr = map;
+
+ if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) {
+ regs[insn->dst_reg].type = PTR_TO_MAP_VALUE;
+ regs[insn->dst_reg].off = aux->map_off;
+ if (map_value_has_spin_lock(map))
+ regs[insn->dst_reg].id = ++env->id_gen;
+ } else if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+ regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
+ } else {
+ verbose(env, "bpf verifier is misconfigured\n");
+ return -EINVAL;
+ }
- regs[insn->dst_reg].type = CONST_PTR_TO_MAP;
- regs[insn->dst_reg].map_ptr = ld_imm64_to_map_ptr(insn);
return 0;
}
@@ -5150,6 +5366,7 @@ static int check_return_code(struct bpf_verifier_env *env)
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_CGROUP_DEVICE:
+ case BPF_PROG_TYPE_CGROUP_SYSCTL:
break;
default:
return 0;
@@ -5220,10 +5437,6 @@ enum {
#define STATE_LIST_MARK ((struct bpf_verifier_state_list *) -1L)
-static int *insn_stack; /* stack of insns to process */
-static int cur_stack; /* current stack index */
-static int *insn_state;
-
/* t, w, e - match pseudo-code above:
* t - index of current instruction
* w - next instruction
@@ -5231,6 +5444,9 @@ static int *insn_state;
*/
static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
{
+ int *insn_stack = env->cfg.insn_stack;
+ int *insn_state = env->cfg.insn_state;
+
if (e == FALLTHROUGH && insn_state[t] >= (DISCOVERED | FALLTHROUGH))
return 0;
@@ -5251,9 +5467,9 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
/* tree-edge */
insn_state[t] = DISCOVERED | e;
insn_state[w] = DISCOVERED;
- if (cur_stack >= env->prog->len)
+ if (env->cfg.cur_stack >= env->prog->len)
return -E2BIG;
- insn_stack[cur_stack++] = w;
+ insn_stack[env->cfg.cur_stack++] = w;
return 1;
} else if ((insn_state[w] & 0xF0) == DISCOVERED) {
verbose_linfo(env, t, "%d: ", t);
@@ -5277,27 +5493,28 @@ static int check_cfg(struct bpf_verifier_env *env)
{
struct bpf_insn *insns = env->prog->insnsi;
int insn_cnt = env->prog->len;
+ int *insn_stack, *insn_state;
int ret = 0;
int i, t;
- insn_state = kcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+ insn_state = env->cfg.insn_state = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
if (!insn_state)
return -ENOMEM;
- insn_stack = kcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
+ insn_stack = env->cfg.insn_stack = kvcalloc(insn_cnt, sizeof(int), GFP_KERNEL);
if (!insn_stack) {
- kfree(insn_state);
+ kvfree(insn_state);
return -ENOMEM;
}
insn_state[0] = DISCOVERED; /* mark 1st insn as discovered */
insn_stack[0] = 0; /* 0 is the first instruction */
- cur_stack = 1;
+ env->cfg.cur_stack = 1;
peek_stack:
- if (cur_stack == 0)
+ if (env->cfg.cur_stack == 0)
goto check_state;
- t = insn_stack[cur_stack - 1];
+ t = insn_stack[env->cfg.cur_stack - 1];
if (BPF_CLASS(insns[t].code) == BPF_JMP ||
BPF_CLASS(insns[t].code) == BPF_JMP32) {
@@ -5366,7 +5583,7 @@ peek_stack:
mark_explored:
insn_state[t] = EXPLORED;
- if (cur_stack-- <= 0) {
+ if (env->cfg.cur_stack-- <= 0) {
verbose(env, "pop stack internal bug\n");
ret = -EFAULT;
goto err_free;
@@ -5384,8 +5601,9 @@ check_state:
ret = 0; /* cfg looks good */
err_free:
- kfree(insn_state);
- kfree(insn_stack);
+ kvfree(insn_state);
+ kvfree(insn_stack);
+ env->cfg.insn_state = env->cfg.insn_stack = NULL;
return ret;
}
@@ -6074,6 +6292,22 @@ static bool states_equal(struct bpf_verifier_env *env,
return true;
}
+static int propagate_liveness_reg(struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg,
+ struct bpf_reg_state *parent_reg)
+{
+ int err;
+
+ if (parent_reg->live & REG_LIVE_READ || !(reg->live & REG_LIVE_READ))
+ return 0;
+
+ err = mark_reg_read(env, reg, parent_reg);
+ if (err)
+ return err;
+
+ return 0;
+}
+
/* A write screens off any subsequent reads; but write marks come from the
* straight-line code between a state and its parent. When we arrive at an
* equivalent state (jump target or such) we didn't arrive by the straight-line
@@ -6085,8 +6319,9 @@ static int propagate_liveness(struct bpf_verifier_env *env,
const struct bpf_verifier_state *vstate,
struct bpf_verifier_state *vparent)
{
- int i, frame, err = 0;
+ struct bpf_reg_state *state_reg, *parent_reg;
struct bpf_func_state *state, *parent;
+ int i, frame, err = 0;
if (vparent->curframe != vstate->curframe) {
WARN(1, "propagate_live: parent frame %d current frame %d\n",
@@ -6096,30 +6331,27 @@ static int propagate_liveness(struct bpf_verifier_env *env,
/* Propagate read liveness of registers... */
BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG);
for (frame = 0; frame <= vstate->curframe; frame++) {
+ parent = vparent->frame[frame];
+ state = vstate->frame[frame];
+ parent_reg = parent->regs;
+ state_reg = state->regs;
/* We don't need to worry about FP liveness, it's read-only */
for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) {
- if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ)
- continue;
- if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) {
- err = mark_reg_read(env, &vstate->frame[frame]->regs[i],
- &vparent->frame[frame]->regs[i]);
- if (err)
- return err;
- }
+ err = propagate_liveness_reg(env, &state_reg[i],
+ &parent_reg[i]);
+ if (err)
+ return err;
}
- }
- /* ... and stack slots */
- for (frame = 0; frame <= vstate->curframe; frame++) {
- state = vstate->frame[frame];
- parent = vparent->frame[frame];
+ /* Propagate stack slots. */
for (i = 0; i < state->allocated_stack / BPF_REG_SIZE &&
i < parent->allocated_stack / BPF_REG_SIZE; i++) {
- if (parent->stack[i].spilled_ptr.live & REG_LIVE_READ)
- continue;
- if (state->stack[i].spilled_ptr.live & REG_LIVE_READ)
- mark_reg_read(env, &state->stack[i].spilled_ptr,
- &parent->stack[i].spilled_ptr);
+ parent_reg = &parent->stack[i].spilled_ptr;
+ state_reg = &state->stack[i].spilled_ptr;
+ err = propagate_liveness_reg(env, state_reg,
+ parent_reg);
+ if (err)
+ return err;
}
}
return err;
@@ -6128,11 +6360,13 @@ static int propagate_liveness(struct bpf_verifier_env *env,
static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
{
struct bpf_verifier_state_list *new_sl;
- struct bpf_verifier_state_list *sl;
+ struct bpf_verifier_state_list *sl, **pprev;
struct bpf_verifier_state *cur = env->cur_state, *new;
int i, j, err, states_cnt = 0;
- sl = env->explored_states[insn_idx];
+ pprev = &env->explored_states[insn_idx];
+ sl = *pprev;
+
if (!sl)
/* this 'insn_idx' instruction wasn't marked, so we will not
* be doing state search here
@@ -6143,6 +6377,7 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
while (sl != STATE_LIST_MARK) {
if (states_equal(env, &sl->state, cur)) {
+ sl->hit_cnt++;
/* reached equivalent register/stack state,
* prune the search.
* Registers read by the continuation are read by us.
@@ -6158,10 +6393,40 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
return err;
return 1;
}
- sl = sl->next;
states_cnt++;
+ sl->miss_cnt++;
+ /* heuristic to determine whether this state is beneficial
+ * to keep checking from state equivalence point of view.
+ * Higher numbers increase max_states_per_insn and verification time,
+ * but do not meaningfully decrease insn_processed.
+ */
+ if (sl->miss_cnt > sl->hit_cnt * 3 + 3) {
+ /* the state is unlikely to be useful. Remove it to
+ * speed up verification
+ */
+ *pprev = sl->next;
+ if (sl->state.frame[0]->regs[0].live & REG_LIVE_DONE) {
+ free_verifier_state(&sl->state, false);
+ kfree(sl);
+ env->peak_states--;
+ } else {
+ /* cannot free this state, since parentage chain may
+ * walk it later. Add it for free_list instead to
+ * be freed at the end of verification
+ */
+ sl->next = env->free_list;
+ env->free_list = sl;
+ }
+ sl = *pprev;
+ continue;
+ }
+ pprev = &sl->next;
+ sl = *pprev;
}
+ if (env->max_states_per_insn < states_cnt)
+ env->max_states_per_insn = states_cnt;
+
if (!env->allow_ptr_leaks && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
return 0;
@@ -6175,6 +6440,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
new_sl = kzalloc(sizeof(struct bpf_verifier_state_list), GFP_KERNEL);
if (!new_sl)
return -ENOMEM;
+ env->total_states++;
+ env->peak_states++;
/* add new state to the head of linked list */
new = &new_sl->state;
@@ -6259,8 +6526,7 @@ static int do_check(struct bpf_verifier_env *env)
struct bpf_verifier_state *state;
struct bpf_insn *insns = env->prog->insnsi;
struct bpf_reg_state *regs;
- int insn_cnt = env->prog->len, i;
- int insn_processed = 0;
+ int insn_cnt = env->prog->len;
bool do_print_state = false;
env->prev_linfo = NULL;
@@ -6295,10 +6561,10 @@ static int do_check(struct bpf_verifier_env *env)
insn = &insns[env->insn_idx];
class = BPF_CLASS(insn->code);
- if (++insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) {
+ if (++env->insn_processed > BPF_COMPLEXITY_LIMIT_INSNS) {
verbose(env,
"BPF program is too large. Processed %d insn\n",
- insn_processed);
+ env->insn_processed);
return -E2BIG;
}
@@ -6307,7 +6573,7 @@ static int do_check(struct bpf_verifier_env *env)
return err;
if (err == 1) {
/* found equivalent state, can prune the search */
- if (env->log.level) {
+ if (env->log.level & BPF_LOG_LEVEL) {
if (do_print_state)
verbose(env, "\nfrom %d to %d%s: safe\n",
env->prev_insn_idx, env->insn_idx,
@@ -6325,8 +6591,9 @@ static int do_check(struct bpf_verifier_env *env)
if (need_resched())
cond_resched();
- if (env->log.level > 1 || (env->log.level && do_print_state)) {
- if (env->log.level > 1)
+ if (env->log.level & BPF_LOG_LEVEL2 ||
+ (env->log.level & BPF_LOG_LEVEL && do_print_state)) {
+ if (env->log.level & BPF_LOG_LEVEL2)
verbose(env, "%d:", env->insn_idx);
else
verbose(env, "\nfrom %d to %d%s:",
@@ -6337,7 +6604,7 @@ static int do_check(struct bpf_verifier_env *env)
do_print_state = false;
}
- if (env->log.level) {
+ if (env->log.level & BPF_LOG_LEVEL) {
const struct bpf_insn_cbs cbs = {
.cb_print = verbose,
.private_data = env,
@@ -6602,16 +6869,6 @@ process_bpf_exit:
env->insn_idx++;
}
- verbose(env, "processed %d insns (limit %d), stack depth ",
- insn_processed, BPF_COMPLEXITY_LIMIT_INSNS);
- for (i = 0; i < env->subprog_cnt; i++) {
- u32 depth = env->subprog_info[i].stack_depth;
-
- verbose(env, "%d", depth);
- if (i + 1 < env->subprog_cnt)
- verbose(env, "+");
- }
- verbose(env, "\n");
env->prog->aux->stack_depth = env->subprog_info[0].stack_depth;
return 0;
}
@@ -6709,8 +6966,10 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
}
if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW)) {
+ struct bpf_insn_aux_data *aux;
struct bpf_map *map;
struct fd f;
+ u64 addr;
if (i == insn_cnt - 1 || insn[1].code != 0 ||
insn[1].dst_reg != 0 || insn[1].src_reg != 0 ||
@@ -6719,13 +6978,19 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
return -EINVAL;
}
- if (insn->src_reg == 0)
+ if (insn[0].src_reg == 0)
/* valid generic load 64-bit imm */
goto next_insn;
- if (insn[0].src_reg != BPF_PSEUDO_MAP_FD ||
- insn[1].imm != 0) {
- verbose(env, "unrecognized bpf_ld_imm64 insn\n");
+ /* In final convert_pseudo_ld_imm64() step, this is
+ * converted into regular 64-bit imm load insn.
+ */
+ if ((insn[0].src_reg != BPF_PSEUDO_MAP_FD &&
+ insn[0].src_reg != BPF_PSEUDO_MAP_VALUE) ||
+ (insn[0].src_reg == BPF_PSEUDO_MAP_FD &&
+ insn[1].imm != 0)) {
+ verbose(env,
+ "unrecognized bpf_ld_imm64 insn\n");
return -EINVAL;
}
@@ -6743,16 +7008,47 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
return err;
}
- /* store map pointer inside BPF_LD_IMM64 instruction */
- insn[0].imm = (u32) (unsigned long) map;
- insn[1].imm = ((u64) (unsigned long) map) >> 32;
+ aux = &env->insn_aux_data[i];
+ if (insn->src_reg == BPF_PSEUDO_MAP_FD) {
+ addr = (unsigned long)map;
+ } else {
+ u32 off = insn[1].imm;
+
+ if (off >= BPF_MAX_VAR_OFF) {
+ verbose(env, "direct value offset of %u is not allowed\n", off);
+ fdput(f);
+ return -EINVAL;
+ }
+
+ if (!map->ops->map_direct_value_addr) {
+ verbose(env, "no direct value access support for this map type\n");
+ fdput(f);
+ return -EINVAL;
+ }
+
+ err = map->ops->map_direct_value_addr(map, &addr, off);
+ if (err) {
+ verbose(env, "invalid access to map value pointer, value_size=%u off=%u\n",
+ map->value_size, off);
+ fdput(f);
+ return err;
+ }
+
+ aux->map_off = off;
+ addr += off;
+ }
+
+ insn[0].imm = (u32)addr;
+ insn[1].imm = addr >> 32;
/* check whether we recorded this map already */
- for (j = 0; j < env->used_map_cnt; j++)
+ for (j = 0; j < env->used_map_cnt; j++) {
if (env->used_maps[j] == map) {
+ aux->map_index = j;
fdput(f);
goto next_insn;
}
+ }
if (env->used_map_cnt >= MAX_USED_MAPS) {
fdput(f);
@@ -6769,6 +7065,8 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
fdput(f);
return PTR_ERR(map);
}
+
+ aux->map_index = env->used_map_cnt;
env->used_maps[env->used_map_cnt++] = map;
if (bpf_map_is_cgroup_storage(map) &&
@@ -6874,8 +7172,13 @@ static struct bpf_prog *bpf_patch_insn_data(struct bpf_verifier_env *env, u32 of
struct bpf_prog *new_prog;
new_prog = bpf_patch_insn_single(env->prog, off, patch, len);
- if (!new_prog)
+ if (IS_ERR(new_prog)) {
+ if (PTR_ERR(new_prog) == -ERANGE)
+ verbose(env,
+ "insn %d cannot be patched due to 16-bit range\n",
+ env->insn_aux_data[off].orig_idx);
return NULL;
+ }
if (adjust_insn_aux_data(env, new_prog->len, off, len))
return NULL;
adjust_subprog_starts(env, off, len);
@@ -7413,9 +7716,8 @@ static int jit_subprogs(struct bpf_verifier_env *env)
insn->src_reg != BPF_PSEUDO_CALL)
continue;
subprog = insn->off;
- insn->imm = (u64 (*)(u64, u64, u64, u64, u64))
- func[subprog]->bpf_func -
- __bpf_call_base;
+ insn->imm = BPF_CAST_CALL(func[subprog]->bpf_func) -
+ __bpf_call_base;
}
/* we use the aux data to keep a list of the start addresses
@@ -7817,6 +8119,14 @@ static void free_states(struct bpf_verifier_env *env)
struct bpf_verifier_state_list *sl, *sln;
int i;
+ sl = env->free_list;
+ while (sl) {
+ sln = sl->next;
+ free_verifier_state(&sl->state, false);
+ kfree(sl);
+ sl = sln;
+ }
+
if (!env->explored_states)
return;
@@ -7832,12 +8142,37 @@ static void free_states(struct bpf_verifier_env *env)
}
}
- kfree(env->explored_states);
+ kvfree(env->explored_states);
+}
+
+static void print_verification_stats(struct bpf_verifier_env *env)
+{
+ int i;
+
+ if (env->log.level & BPF_LOG_STATS) {
+ verbose(env, "verification time %lld usec\n",
+ div_u64(env->verification_time, 1000));
+ verbose(env, "stack depth ");
+ for (i = 0; i < env->subprog_cnt; i++) {
+ u32 depth = env->subprog_info[i].stack_depth;
+
+ verbose(env, "%d", depth);
+ if (i + 1 < env->subprog_cnt)
+ verbose(env, "+");
+ }
+ verbose(env, "\n");
+ }
+ verbose(env, "processed %d insns (limit %d) max_states_per_insn %d "
+ "total_states %d peak_states %d mark_read %d\n",
+ env->insn_processed, BPF_COMPLEXITY_LIMIT_INSNS,
+ env->max_states_per_insn, env->total_states,
+ env->peak_states, env->longest_mark_read_walk);
}
int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
union bpf_attr __user *uattr)
{
+ u64 start_time = ktime_get_ns();
struct bpf_verifier_env *env;
struct bpf_verifier_log *log;
int i, len, ret = -EINVAL;
@@ -7865,9 +8200,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
env->insn_aux_data[i].orig_idx = i;
env->prog = *prog;
env->ops = bpf_verifier_ops[env->prog->type];
+ is_priv = capable(CAP_SYS_ADMIN);
/* grab the mutex to protect few globals used by verifier */
- mutex_lock(&bpf_verifier_lock);
+ if (!is_priv)
+ mutex_lock(&bpf_verifier_lock);
if (attr->log_level || attr->log_buf || attr->log_size) {
/* user requested verbose verifier output
@@ -7879,8 +8216,8 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
ret = -EINVAL;
/* log attributes have to be sane */
- if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 ||
- !log->level || !log->ubuf)
+ if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 ||
+ !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK)
goto err_unlock;
}
@@ -7890,7 +8227,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
if (attr->prog_flags & BPF_F_ANY_ALIGNMENT)
env->strict_alignment = false;
- is_priv = capable(CAP_SYS_ADMIN);
env->allow_ptr_leaks = is_priv;
ret = replace_map_fd_with_map_ptr(env);
@@ -7903,7 +8239,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr,
goto skip_full_check;
}
- env->explored_states = kcalloc(env->prog->len,
+ env->explored_states = kvcalloc(env->prog->len,
sizeof(struct bpf_verifier_state_list *),
GFP_USER);
ret = -ENOMEM;
@@ -7961,6 +8297,9 @@ skip_full_check:
if (ret == 0)
ret = fixup_call_args(env);
+ env->verification_time = ktime_get_ns() - start_time;
+ print_verification_stats(env);
+
if (log->level && bpf_verifier_log_full(log))
ret = -ENOSPC;
if (log->level && !log->ubuf) {
@@ -8000,7 +8339,8 @@ err_release_maps:
release_maps(env);
*prog = env->prog;
err_unlock:
- mutex_unlock(&bpf_verifier_lock);
+ if (!is_priv)
+ mutex_unlock(&bpf_verifier_lock);
vfree(env->insn_aux_data);
err_free_env:
kfree(env);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 15:39:34 +0000