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Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c96
1 files changed, 47 insertions, 49 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 14d350a25d5d..5ce5364ce898 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -262,7 +262,7 @@ struct bpf_call_arg_meta {
struct btf *ret_btf;
u32 ret_btf_id;
u32 subprogno;
- struct bpf_map_value_off_desc *kptr_off_desc;
+ struct btf_field *kptr_field;
u8 uninit_dynptr_regno;
};
@@ -3674,15 +3674,15 @@ int check_ptr_off_reg(struct bpf_verifier_env *env,
}
static int map_kptr_match_type(struct bpf_verifier_env *env,
- struct bpf_map_value_off_desc *off_desc,
+ struct btf_field *kptr_field,
struct bpf_reg_state *reg, u32 regno)
{
- const char *targ_name = kernel_type_name(off_desc->kptr.btf, off_desc->kptr.btf_id);
+ const char *targ_name = kernel_type_name(kptr_field->kptr.btf, kptr_field->kptr.btf_id);
int perm_flags = PTR_MAYBE_NULL;
const char *reg_name = "";
/* Only unreferenced case accepts untrusted pointers */
- if (off_desc->type == BPF_KPTR_UNREF)
+ if (kptr_field->type == BPF_KPTR_UNREF)
perm_flags |= PTR_UNTRUSTED;
if (base_type(reg->type) != PTR_TO_BTF_ID || (type_flag(reg->type) & ~perm_flags))
@@ -3729,15 +3729,15 @@ static int map_kptr_match_type(struct bpf_verifier_env *env,
* strict mode to true for type match.
*/
if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, reg->off,
- off_desc->kptr.btf, off_desc->kptr.btf_id,
- off_desc->type == BPF_KPTR_REF))
+ kptr_field->kptr.btf, kptr_field->kptr.btf_id,
+ kptr_field->type == BPF_KPTR_REF))
goto bad_type;
return 0;
bad_type:
verbose(env, "invalid kptr access, R%d type=%s%s ", regno,
reg_type_str(env, reg->type), reg_name);
verbose(env, "expected=%s%s", reg_type_str(env, PTR_TO_BTF_ID), targ_name);
- if (off_desc->type == BPF_KPTR_UNREF)
+ if (kptr_field->type == BPF_KPTR_UNREF)
verbose(env, " or %s%s\n", reg_type_str(env, PTR_TO_BTF_ID | PTR_UNTRUSTED),
targ_name);
else
@@ -3747,7 +3747,7 @@ bad_type:
static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
int value_regno, int insn_idx,
- struct bpf_map_value_off_desc *off_desc)
+ struct btf_field *kptr_field)
{
struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
int class = BPF_CLASS(insn->code);
@@ -3757,7 +3757,7 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
* - Reject cases where variable offset may touch kptr
* - size of access (must be BPF_DW)
* - tnum_is_const(reg->var_off)
- * - off_desc->offset == off + reg->var_off.value
+ * - kptr_field->offset == off + reg->var_off.value
*/
/* Only BPF_[LDX,STX,ST] | BPF_MEM | BPF_DW is supported */
if (BPF_MODE(insn->code) != BPF_MEM) {
@@ -3768,7 +3768,7 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
/* We only allow loading referenced kptr, since it will be marked as
* untrusted, similar to unreferenced kptr.
*/
- if (class != BPF_LDX && off_desc->type == BPF_KPTR_REF) {
+ if (class != BPF_LDX && kptr_field->type == BPF_KPTR_REF) {
verbose(env, "store to referenced kptr disallowed\n");
return -EACCES;
}
@@ -3778,19 +3778,19 @@ static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno,
/* We can simply mark the value_regno receiving the pointer
* value from map as PTR_TO_BTF_ID, with the correct type.
*/
- mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, off_desc->kptr.btf,
- off_desc->kptr.btf_id, PTR_MAYBE_NULL | PTR_UNTRUSTED);
+ mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, kptr_field->kptr.btf,
+ kptr_field->kptr.btf_id, PTR_MAYBE_NULL | PTR_UNTRUSTED);
/* For mark_ptr_or_null_reg */
val_reg->id = ++env->id_gen;
} else if (class == BPF_STX) {
val_reg = reg_state(env, value_regno);
if (!register_is_null(val_reg) &&
- map_kptr_match_type(env, off_desc, val_reg, value_regno))
+ map_kptr_match_type(env, kptr_field, val_reg, value_regno))
return -EACCES;
} else if (class == BPF_ST) {
if (insn->imm) {
verbose(env, "BPF_ST imm must be 0 when storing to kptr at off=%u\n",
- off_desc->offset);
+ kptr_field->offset);
return -EACCES;
}
} else {
@@ -3809,7 +3809,8 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
struct bpf_func_state *state = vstate->frame[vstate->curframe];
struct bpf_reg_state *reg = &state->regs[regno];
struct bpf_map *map = reg->map_ptr;
- int err;
+ struct btf_record *rec;
+ int err, i;
err = check_mem_region_access(env, regno, off, size, map->value_size,
zero_size_allowed);
@@ -3839,15 +3840,18 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
return -EACCES;
}
}
- if (map_value_has_kptrs(map)) {
- struct bpf_map_value_off *tab = map->kptr_off_tab;
- int i;
-
- for (i = 0; i < tab->nr_off; i++) {
- u32 p = tab->off[i].offset;
-
- if (reg->smin_value + off < p + sizeof(u64) &&
- p < reg->umax_value + off + size) {
+ if (IS_ERR_OR_NULL(map->record))
+ return 0;
+ rec = map->record;
+ for (i = 0; i < rec->cnt; i++) {
+ struct btf_field *field = &rec->fields[i];
+ u32 p = field->offset;
+
+ if (reg->smin_value + off < p + btf_field_type_size(field->type) &&
+ p < reg->umax_value + off + size) {
+ switch (field->type) {
+ case BPF_KPTR_UNREF:
+ case BPF_KPTR_REF:
if (src != ACCESS_DIRECT) {
verbose(env, "kptr cannot be accessed indirectly by helper\n");
return -EACCES;
@@ -3866,10 +3870,13 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno,
return -EACCES;
}
break;
+ default:
+ verbose(env, "field cannot be accessed directly by load/store\n");
+ return -EACCES;
}
}
}
- return err;
+ return 0;
}
#define MAX_PACKET_OFF 0xffff
@@ -4742,7 +4749,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
if (value_regno >= 0)
mark_reg_unknown(env, regs, value_regno);
} else if (reg->type == PTR_TO_MAP_VALUE) {
- struct bpf_map_value_off_desc *kptr_off_desc = NULL;
+ struct btf_field *kptr_field = NULL;
if (t == BPF_WRITE && value_regno >= 0 &&
is_pointer_value(env, value_regno)) {
@@ -4756,11 +4763,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn
if (err)
return err;
if (tnum_is_const(reg->var_off))
- kptr_off_desc = bpf_map_kptr_off_contains(reg->map_ptr,
- off + reg->var_off.value);
- if (kptr_off_desc) {
- err = check_map_kptr_access(env, regno, value_regno, insn_idx,
- kptr_off_desc);
+ kptr_field = btf_record_find(reg->map_ptr->record,
+ off + reg->var_off.value, BPF_KPTR);
+ if (kptr_field) {
+ err = check_map_kptr_access(env, regno, value_regno, insn_idx, kptr_field);
} else if (t == BPF_READ && value_regno >= 0) {
struct bpf_map *map = reg->map_ptr;
@@ -5527,10 +5533,9 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
struct bpf_call_arg_meta *meta)
{
struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
- struct bpf_map_value_off_desc *off_desc;
struct bpf_map *map_ptr = reg->map_ptr;
+ struct btf_field *kptr_field;
u32 kptr_off;
- int ret;
if (!tnum_is_const(reg->var_off)) {
verbose(env,
@@ -5543,30 +5548,23 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno,
map_ptr->name);
return -EINVAL;
}
- if (!map_value_has_kptrs(map_ptr)) {
- ret = PTR_ERR_OR_ZERO(map_ptr->kptr_off_tab);
- if (ret == -E2BIG)
- verbose(env, "map '%s' has more than %d kptr\n", map_ptr->name,
- BPF_MAP_VALUE_OFF_MAX);
- else if (ret == -EEXIST)
- verbose(env, "map '%s' has repeating kptr BTF tags\n", map_ptr->name);
- else
- verbose(env, "map '%s' has no valid kptr\n", map_ptr->name);
+ if (!btf_record_has_field(map_ptr->record, BPF_KPTR)) {
+ verbose(env, "map '%s' has no valid kptr\n", map_ptr->name);
return -EINVAL;
}
meta->map_ptr = map_ptr;
kptr_off = reg->off + reg->var_off.value;
- off_desc = bpf_map_kptr_off_contains(map_ptr, kptr_off);
- if (!off_desc) {
+ kptr_field = btf_record_find(map_ptr->record, kptr_off, BPF_KPTR);
+ if (!kptr_field) {
verbose(env, "off=%d doesn't point to kptr\n", kptr_off);
return -EACCES;
}
- if (off_desc->type != BPF_KPTR_REF) {
+ if (kptr_field->type != BPF_KPTR_REF) {
verbose(env, "off=%d kptr isn't referenced kptr\n", kptr_off);
return -EACCES;
}
- meta->kptr_off_desc = off_desc;
+ meta->kptr_field = kptr_field;
return 0;
}
@@ -5788,7 +5786,7 @@ found:
}
if (meta->func_id == BPF_FUNC_kptr_xchg) {
- if (map_kptr_match_type(env, meta->kptr_off_desc, reg, regno))
+ if (map_kptr_match_type(env, meta->kptr_field, reg, regno))
return -EACCES;
} else {
if (arg_btf_id == BPF_PTR_POISON) {
@@ -7536,8 +7534,8 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
mark_reg_known_zero(env, regs, BPF_REG_0);
regs[BPF_REG_0].type = PTR_TO_BTF_ID | ret_flag;
if (func_id == BPF_FUNC_kptr_xchg) {
- ret_btf = meta.kptr_off_desc->kptr.btf;
- ret_btf_id = meta.kptr_off_desc->kptr.btf_id;
+ ret_btf = meta.kptr_field->kptr.btf;
+ ret_btf_id = meta.kptr_field->kptr.btf_id;
} else {
if (fn->ret_btf_id == BPF_PTR_POISON) {
verbose(env, "verifier internal error:");