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Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c89
1 files changed, 49 insertions, 40 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 034ef81f935b..7d530ce8719d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -907,7 +907,8 @@ static const int caller_saved[CALLER_SAVED_REGS] = {
BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
};
-static void __mark_reg_not_init(struct bpf_reg_state *reg);
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg);
/* Mark the unknown part of a register (variable offset or scalar value) as
* known to have the value @imm.
@@ -945,7 +946,7 @@ static void mark_reg_known_zero(struct bpf_verifier_env *env,
verbose(env, "mark_reg_known_zero(regs, %u)\n", regno);
/* Something bad happened, let's kill all regs */
for (regno = 0; regno < MAX_BPF_REG; regno++)
- __mark_reg_not_init(regs + regno);
+ __mark_reg_not_init(env, regs + regno);
return;
}
__mark_reg_known_zero(regs + regno);
@@ -1054,7 +1055,8 @@ static void __mark_reg_unbounded(struct bpf_reg_state *reg)
}
/* Mark a register as having a completely unknown (scalar) value. */
-static void __mark_reg_unknown(struct bpf_reg_state *reg)
+static void __mark_reg_unknown(const struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg)
{
/*
* Clear type, id, off, and union(map_ptr, range) and
@@ -1064,6 +1066,8 @@ static void __mark_reg_unknown(struct bpf_reg_state *reg)
reg->type = SCALAR_VALUE;
reg->var_off = tnum_unknown;
reg->frameno = 0;
+ reg->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
+ true : false;
__mark_reg_unbounded(reg);
}
@@ -1074,19 +1078,16 @@ static void mark_reg_unknown(struct bpf_verifier_env *env,
verbose(env, "mark_reg_unknown(regs, %u)\n", regno);
/* Something bad happened, let's kill all regs except FP */
for (regno = 0; regno < BPF_REG_FP; regno++)
- __mark_reg_not_init(regs + regno);
+ __mark_reg_not_init(env, regs + regno);
return;
}
- regs += regno;
- __mark_reg_unknown(regs);
- /* constant backtracking is enabled for root without bpf2bpf calls */
- regs->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
- true : false;
+ __mark_reg_unknown(env, regs + regno);
}
-static void __mark_reg_not_init(struct bpf_reg_state *reg)
+static void __mark_reg_not_init(const struct bpf_verifier_env *env,
+ struct bpf_reg_state *reg)
{
- __mark_reg_unknown(reg);
+ __mark_reg_unknown(env, reg);
reg->type = NOT_INIT;
}
@@ -1097,10 +1098,10 @@ static void mark_reg_not_init(struct bpf_verifier_env *env,
verbose(env, "mark_reg_not_init(regs, %u)\n", regno);
/* Something bad happened, let's kill all regs except FP */
for (regno = 0; regno < BPF_REG_FP; regno++)
- __mark_reg_not_init(regs + regno);
+ __mark_reg_not_init(env, regs + regno);
return;
}
- __mark_reg_not_init(regs + regno);
+ __mark_reg_not_init(env, regs + regno);
}
#define DEF_NOT_SUBREG (0)
@@ -3234,7 +3235,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
}
if (state->stack[spi].slot_type[0] == STACK_SPILL &&
state->stack[spi].spilled_ptr.type == SCALAR_VALUE) {
- __mark_reg_unknown(&state->stack[spi].spilled_ptr);
+ __mark_reg_unknown(env, &state->stack[spi].spilled_ptr);
for (j = 0; j < BPF_REG_SIZE; j++)
state->stack[spi].slot_type[j] = STACK_MISC;
goto mark;
@@ -3892,7 +3893,7 @@ static void __clear_all_pkt_pointers(struct bpf_verifier_env *env,
if (!reg)
continue;
if (reg_is_pkt_pointer_any(reg))
- __mark_reg_unknown(reg);
+ __mark_reg_unknown(env, reg);
}
}
@@ -3920,7 +3921,7 @@ static void release_reg_references(struct bpf_verifier_env *env,
if (!reg)
continue;
if (reg->ref_obj_id == ref_obj_id)
- __mark_reg_unknown(reg);
+ __mark_reg_unknown(env, reg);
}
}
@@ -4134,6 +4135,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
struct bpf_map *map = meta->map_ptr;
struct tnum range;
u64 val;
+ int err;
if (func_id != BPF_FUNC_tail_call)
return 0;
@@ -4150,6 +4152,10 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
return 0;
}
+ err = mark_chain_precision(env, BPF_REG_3);
+ if (err)
+ return err;
+
val = reg->var_off.value;
if (bpf_map_key_unseen(aux))
bpf_map_key_store(aux, val);
@@ -4577,7 +4583,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
/* Taint dst register if offset had invalid bounds derived from
* e.g. dead branches.
*/
- __mark_reg_unknown(dst_reg);
+ __mark_reg_unknown(env, dst_reg);
return 0;
}
@@ -4829,13 +4835,13 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
/* Taint dst register if offset had invalid bounds derived from
* e.g. dead branches.
*/
- __mark_reg_unknown(dst_reg);
+ __mark_reg_unknown(env, dst_reg);
return 0;
}
if (!src_known &&
opcode != BPF_ADD && opcode != BPF_SUB && opcode != BPF_AND) {
- __mark_reg_unknown(dst_reg);
+ __mark_reg_unknown(env, dst_reg);
return 0;
}
@@ -5043,9 +5049,16 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env,
/* Upon reaching here, src_known is true and
* umax_val is equal to umin_val.
*/
- dst_reg->smin_value >>= umin_val;
- dst_reg->smax_value >>= umin_val;
- dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val);
+ if (insn_bitness == 32) {
+ dst_reg->smin_value = (u32)(((s32)dst_reg->smin_value) >> umin_val);
+ dst_reg->smax_value = (u32)(((s32)dst_reg->smax_value) >> umin_val);
+ } else {
+ dst_reg->smin_value >>= umin_val;
+ dst_reg->smax_value >>= umin_val;
+ }
+
+ dst_reg->var_off = tnum_arshift(dst_reg->var_off, umin_val,
+ insn_bitness);
/* blow away the dst_reg umin_value/umax_value and rely on
* dst_reg var_off to refine the result.
@@ -6258,6 +6271,7 @@ static bool may_access_skb(enum bpf_prog_type type)
static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
{
struct bpf_reg_state *regs = cur_regs(env);
+ static const int ctx_reg = BPF_REG_6;
u8 mode = BPF_MODE(insn->code);
int i, err;
@@ -6291,7 +6305,7 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
}
/* check whether implicit source operand (register R6) is readable */
- err = check_reg_arg(env, BPF_REG_6, SRC_OP);
+ err = check_reg_arg(env, ctx_reg, SRC_OP);
if (err)
return err;
@@ -6310,7 +6324,7 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
return -EINVAL;
}
- if (regs[BPF_REG_6].type != PTR_TO_CTX) {
+ if (regs[ctx_reg].type != PTR_TO_CTX) {
verbose(env,
"at the time of BPF_LD_ABS|IND R6 != pointer to skb\n");
return -EINVAL;
@@ -6323,6 +6337,10 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
return err;
}
+ err = check_ctx_reg(env, &regs[ctx_reg], ctx_reg);
+ if (err < 0)
+ return err;
+
/* reset caller saved regs to unreadable */
for (i = 0; i < CALLER_SAVED_REGS; i++) {
mark_reg_not_init(env, regs, caller_saved[i]);
@@ -6977,7 +6995,7 @@ static void clean_func_state(struct bpf_verifier_env *env,
/* since the register is unused, clear its state
* to make further comparison simpler
*/
- __mark_reg_not_init(&st->regs[i]);
+ __mark_reg_not_init(env, &st->regs[i]);
}
for (i = 0; i < st->allocated_stack / BPF_REG_SIZE; i++) {
@@ -6985,7 +7003,7 @@ static void clean_func_state(struct bpf_verifier_env *env,
/* liveness must not touch this stack slot anymore */
st->stack[i].spilled_ptr.live |= REG_LIVE_DONE;
if (!(live & REG_LIVE_READ)) {
- __mark_reg_not_init(&st->stack[i].spilled_ptr);
+ __mark_reg_not_init(env, &st->stack[i].spilled_ptr);
for (j = 0; j < BPF_REG_SIZE; j++)
st->stack[i].slot_type[j] = STACK_INVALID;
}
@@ -8268,7 +8286,7 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env)
env->used_maps[env->used_map_cnt++] = map;
if (bpf_map_is_cgroup_storage(map) &&
- bpf_cgroup_storage_assign(env->prog, map)) {
+ bpf_cgroup_storage_assign(env->prog->aux, map)) {
verbose(env, "only one cgroup storage of each type is allowed\n");
fdput(f);
return -EBUSY;
@@ -8298,18 +8316,8 @@ next_insn:
/* drop refcnt of maps used by the rejected program */
static void release_maps(struct bpf_verifier_env *env)
{
- enum bpf_cgroup_storage_type stype;
- int i;
-
- for_each_cgroup_storage_type(stype) {
- if (!env->prog->aux->cgroup_storage[stype])
- continue;
- bpf_cgroup_storage_release(env->prog,
- env->prog->aux->cgroup_storage[stype]);
- }
-
- for (i = 0; i < env->used_map_cnt; i++)
- bpf_map_put(env->used_maps[i]);
+ __bpf_free_used_maps(env->prog->aux, env->used_maps,
+ env->used_map_cnt);
}
/* convert pseudo BPF_LD_IMM64 into generic BPF_LD_IMM64 */
@@ -9282,7 +9290,8 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env)
insn->code = BPF_JMP | BPF_TAIL_CALL;
aux = &env->insn_aux_data[i + delta];
- if (prog->jit_requested && !expect_blinding &&
+ if (env->allow_ptr_leaks && !expect_blinding &&
+ prog->jit_requested &&
!bpf_map_key_poisoned(aux) &&
!bpf_map_ptr_poisoned(aux) &&
!bpf_map_ptr_unpriv(aux)) {
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