diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 573 |
1 files changed, 434 insertions, 139 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1c4ebb326785..31e0d33498ac 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -196,7 +196,8 @@ struct bpf_verifier_stack_elem { #define BPF_PRIV_STACK_MIN_SIZE 64 -static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx); +static int acquire_reference(struct bpf_verifier_env *env, int insn_idx); +static int release_reference_nomark(struct bpf_verifier_state *state, int ref_obj_id); static int release_reference(struct bpf_verifier_env *env, int ref_obj_id); static void invalidate_non_owning_refs(struct bpf_verifier_env *env); static bool in_rbtree_lock_required_cb(struct bpf_verifier_env *env); @@ -660,6 +661,11 @@ static int iter_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg, return stack_slot_obj_get_spi(env, reg, "iter", nr_slots); } +static int irq_flag_get_spi(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + return stack_slot_obj_get_spi(env, reg, "irq_flag", 1); +} + static enum bpf_dynptr_type arg_to_dynptr_type(enum bpf_arg_type arg_type) { switch (arg_type & DYNPTR_TYPE_FLAG_MASK) { @@ -771,7 +777,7 @@ static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_ if (clone_ref_obj_id) id = clone_ref_obj_id; else - id = acquire_reference_state(env, insn_idx); + id = acquire_reference(env, insn_idx); if (id < 0) return id; @@ -1033,7 +1039,7 @@ static int mark_stack_slots_iter(struct bpf_verifier_env *env, if (spi < 0) return spi; - id = acquire_reference_state(env, insn_idx); + id = acquire_reference(env, insn_idx); if (id < 0) return id; @@ -1155,10 +1161,136 @@ static int is_iter_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_s return 0; } +static int acquire_irq_state(struct bpf_verifier_env *env, int insn_idx); +static int release_irq_state(struct bpf_verifier_state *state, int id); + +static int mark_stack_slot_irq_flag(struct bpf_verifier_env *env, + struct bpf_kfunc_call_arg_meta *meta, + struct bpf_reg_state *reg, int insn_idx) +{ + struct bpf_func_state *state = func(env, reg); + struct bpf_stack_state *slot; + struct bpf_reg_state *st; + int spi, i, id; + + spi = irq_flag_get_spi(env, reg); + if (spi < 0) + return spi; + + id = acquire_irq_state(env, insn_idx); + if (id < 0) + return id; + + slot = &state->stack[spi]; + st = &slot->spilled_ptr; + + __mark_reg_known_zero(st); + st->type = PTR_TO_STACK; /* we don't have dedicated reg type */ + st->live |= REG_LIVE_WRITTEN; + st->ref_obj_id = id; + + for (i = 0; i < BPF_REG_SIZE; i++) + slot->slot_type[i] = STACK_IRQ_FLAG; + + mark_stack_slot_scratched(env, spi); + return 0; +} + +static int unmark_stack_slot_irq_flag(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + struct bpf_stack_state *slot; + struct bpf_reg_state *st; + int spi, i, err; + + spi = irq_flag_get_spi(env, reg); + if (spi < 0) + return spi; + + slot = &state->stack[spi]; + st = &slot->spilled_ptr; + + err = release_irq_state(env->cur_state, st->ref_obj_id); + WARN_ON_ONCE(err && err != -EACCES); + if (err) { + int insn_idx = 0; + + for (int i = 0; i < env->cur_state->acquired_refs; i++) { + if (env->cur_state->refs[i].id == env->cur_state->active_irq_id) { + insn_idx = env->cur_state->refs[i].insn_idx; + break; + } + } + + verbose(env, "cannot restore irq state out of order, expected id=%d acquired at insn_idx=%d\n", + env->cur_state->active_irq_id, insn_idx); + return err; + } + + __mark_reg_not_init(env, st); + + /* see unmark_stack_slots_dynptr() for why we need to set REG_LIVE_WRITTEN */ + st->live |= REG_LIVE_WRITTEN; + + for (i = 0; i < BPF_REG_SIZE; i++) + slot->slot_type[i] = STACK_INVALID; + + mark_stack_slot_scratched(env, spi); + return 0; +} + +static bool is_irq_flag_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + struct bpf_stack_state *slot; + int spi, i; + + /* For -ERANGE (i.e. spi not falling into allocated stack slots), we + * will do check_mem_access to check and update stack bounds later, so + * return true for that case. + */ + spi = irq_flag_get_spi(env, reg); + if (spi == -ERANGE) + return true; + if (spi < 0) + return false; + + slot = &state->stack[spi]; + + for (i = 0; i < BPF_REG_SIZE; i++) + if (slot->slot_type[i] == STACK_IRQ_FLAG) + return false; + return true; +} + +static int is_irq_flag_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + struct bpf_stack_state *slot; + struct bpf_reg_state *st; + int spi, i; + + spi = irq_flag_get_spi(env, reg); + if (spi < 0) + return -EINVAL; + + slot = &state->stack[spi]; + st = &slot->spilled_ptr; + + if (!st->ref_obj_id) + return -EINVAL; + + for (i = 0; i < BPF_REG_SIZE; i++) + if (slot->slot_type[i] != STACK_IRQ_FLAG) + return -EINVAL; + return 0; +} + /* Check if given stack slot is "special": * - spilled register state (STACK_SPILL); * - dynptr state (STACK_DYNPTR); * - iter state (STACK_ITER). + * - irq flag state (STACK_IRQ_FLAG) */ static bool is_stack_slot_special(const struct bpf_stack_state *stack) { @@ -1168,6 +1300,7 @@ static bool is_stack_slot_special(const struct bpf_stack_state *stack) case STACK_SPILL: case STACK_DYNPTR: case STACK_ITER: + case STACK_IRQ_FLAG: return true; case STACK_INVALID: case STACK_MISC: @@ -1279,15 +1412,18 @@ out: return arr ? arr : ZERO_SIZE_PTR; } -static int copy_reference_state(struct bpf_func_state *dst, const struct bpf_func_state *src) +static int copy_reference_state(struct bpf_verifier_state *dst, const struct bpf_verifier_state *src) { dst->refs = copy_array(dst->refs, src->refs, src->acquired_refs, sizeof(struct bpf_reference_state), GFP_KERNEL); if (!dst->refs) return -ENOMEM; - dst->active_locks = src->active_locks; dst->acquired_refs = src->acquired_refs; + dst->active_locks = src->active_locks; + dst->active_preempt_locks = src->active_preempt_locks; + dst->active_rcu_lock = src->active_rcu_lock; + dst->active_irq_id = src->active_irq_id; return 0; } @@ -1304,7 +1440,7 @@ static int copy_stack_state(struct bpf_func_state *dst, const struct bpf_func_st return 0; } -static int resize_reference_state(struct bpf_func_state *state, size_t n) +static int resize_reference_state(struct bpf_verifier_state *state, size_t n) { state->refs = realloc_array(state->refs, state->acquired_refs, n, sizeof(struct bpf_reference_state)); @@ -1347,94 +1483,128 @@ static int grow_stack_state(struct bpf_verifier_env *env, struct bpf_func_state * On success, returns a valid pointer id to associate with the register * On failure, returns a negative errno. */ -static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx) +static struct bpf_reference_state *acquire_reference_state(struct bpf_verifier_env *env, int insn_idx) { - struct bpf_func_state *state = cur_func(env); + struct bpf_verifier_state *state = env->cur_state; int new_ofs = state->acquired_refs; - int id, err; + int err; err = resize_reference_state(state, state->acquired_refs + 1); if (err) - return err; - id = ++env->id_gen; - state->refs[new_ofs].type = REF_TYPE_PTR; - state->refs[new_ofs].id = id; + return NULL; state->refs[new_ofs].insn_idx = insn_idx; - return id; + return &state->refs[new_ofs]; +} + +static int acquire_reference(struct bpf_verifier_env *env, int insn_idx) +{ + struct bpf_reference_state *s; + + s = acquire_reference_state(env, insn_idx); + if (!s) + return -ENOMEM; + s->type = REF_TYPE_PTR; + s->id = ++env->id_gen; + return s->id; } static int acquire_lock_state(struct bpf_verifier_env *env, int insn_idx, enum ref_state_type type, int id, void *ptr) { - struct bpf_func_state *state = cur_func(env); - int new_ofs = state->acquired_refs; - int err; + struct bpf_verifier_state *state = env->cur_state; + struct bpf_reference_state *s; - err = resize_reference_state(state, state->acquired_refs + 1); - if (err) - return err; - state->refs[new_ofs].type = type; - state->refs[new_ofs].id = id; - state->refs[new_ofs].insn_idx = insn_idx; - state->refs[new_ofs].ptr = ptr; + s = acquire_reference_state(env, insn_idx); + s->type = type; + s->id = id; + s->ptr = ptr; state->active_locks++; return 0; } -/* release function corresponding to acquire_reference_state(). Idempotent. */ -static int release_reference_state(struct bpf_func_state *state, int ptr_id) +static int acquire_irq_state(struct bpf_verifier_env *env, int insn_idx) +{ + struct bpf_verifier_state *state = env->cur_state; + struct bpf_reference_state *s; + + s = acquire_reference_state(env, insn_idx); + if (!s) + return -ENOMEM; + s->type = REF_TYPE_IRQ; + s->id = ++env->id_gen; + + state->active_irq_id = s->id; + return s->id; +} + +static void release_reference_state(struct bpf_verifier_state *state, int idx) { - int i, last_idx; + int last_idx; + size_t rem; + /* IRQ state requires the relative ordering of elements remaining the + * same, since it relies on the refs array to behave as a stack, so that + * it can detect out-of-order IRQ restore. Hence use memmove to shift + * the array instead of swapping the final element into the deleted idx. + */ last_idx = state->acquired_refs - 1; + rem = state->acquired_refs - idx - 1; + if (last_idx && idx != last_idx) + memmove(&state->refs[idx], &state->refs[idx + 1], sizeof(*state->refs) * rem); + memset(&state->refs[last_idx], 0, sizeof(*state->refs)); + state->acquired_refs--; + return; +} + +static int release_lock_state(struct bpf_verifier_state *state, int type, int id, void *ptr) +{ + int i; + for (i = 0; i < state->acquired_refs; i++) { - if (state->refs[i].type != REF_TYPE_PTR) + if (state->refs[i].type != type) continue; - if (state->refs[i].id == ptr_id) { - if (last_idx && i != last_idx) - memcpy(&state->refs[i], &state->refs[last_idx], - sizeof(*state->refs)); - memset(&state->refs[last_idx], 0, sizeof(*state->refs)); - state->acquired_refs--; + if (state->refs[i].id == id && state->refs[i].ptr == ptr) { + release_reference_state(state, i); + state->active_locks--; return 0; } } return -EINVAL; } -static int release_lock_state(struct bpf_func_state *state, int type, int id, void *ptr) +static int release_irq_state(struct bpf_verifier_state *state, int id) { - int i, last_idx; + u32 prev_id = 0; + int i; + + if (id != state->active_irq_id) + return -EACCES; - last_idx = state->acquired_refs - 1; for (i = 0; i < state->acquired_refs; i++) { - if (state->refs[i].type != type) + if (state->refs[i].type != REF_TYPE_IRQ) continue; - if (state->refs[i].id == id && state->refs[i].ptr == ptr) { - if (last_idx && i != last_idx) - memcpy(&state->refs[i], &state->refs[last_idx], - sizeof(*state->refs)); - memset(&state->refs[last_idx], 0, sizeof(*state->refs)); - state->acquired_refs--; - state->active_locks--; + if (state->refs[i].id == id) { + release_reference_state(state, i); + state->active_irq_id = prev_id; return 0; + } else { + prev_id = state->refs[i].id; } } return -EINVAL; } -static struct bpf_reference_state *find_lock_state(struct bpf_verifier_env *env, enum ref_state_type type, +static struct bpf_reference_state *find_lock_state(struct bpf_verifier_state *state, enum ref_state_type type, int id, void *ptr) { - struct bpf_func_state *state = cur_func(env); int i; for (i = 0; i < state->acquired_refs; i++) { struct bpf_reference_state *s = &state->refs[i]; - if (s->type == REF_TYPE_PTR || s->type != type) + if (s->type != type) continue; if (s->id == id && s->ptr == ptr) @@ -1447,7 +1617,6 @@ static void free_func_state(struct bpf_func_state *state) { if (!state) return; - kfree(state->refs); kfree(state->stack); kfree(state); } @@ -1461,6 +1630,7 @@ static void free_verifier_state(struct bpf_verifier_state *state, free_func_state(state->frame[i]); state->frame[i] = NULL; } + kfree(state->refs); if (free_self) kfree(state); } @@ -1471,12 +1641,7 @@ static void free_verifier_state(struct bpf_verifier_state *state, static int copy_func_state(struct bpf_func_state *dst, const struct bpf_func_state *src) { - int err; - - memcpy(dst, src, offsetof(struct bpf_func_state, acquired_refs)); - err = copy_reference_state(dst, src); - if (err) - return err; + memcpy(dst, src, offsetof(struct bpf_func_state, stack)); return copy_stack_state(dst, src); } @@ -1493,9 +1658,10 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state, free_func_state(dst_state->frame[i]); dst_state->frame[i] = NULL; } + err = copy_reference_state(dst_state, src); + if (err) + return err; dst_state->speculative = src->speculative; - dst_state->active_rcu_lock = src->active_rcu_lock; - dst_state->active_preempt_lock = src->active_preempt_lock; dst_state->in_sleepable = src->in_sleepable; dst_state->curframe = src->curframe; dst_state->branches = src->branches; @@ -3202,10 +3368,27 @@ static int mark_reg_read(struct bpf_verifier_env *env, return 0; } -static int mark_dynptr_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +static int mark_stack_slot_obj_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + int spi, int nr_slots) { struct bpf_func_state *state = func(env, reg); - int spi, ret; + int err, i; + + for (i = 0; i < nr_slots; i++) { + struct bpf_reg_state *st = &state->stack[spi - i].spilled_ptr; + + err = mark_reg_read(env, st, st->parent, REG_LIVE_READ64); + if (err) + return err; + + mark_stack_slot_scratched(env, spi - i); + } + return 0; +} + +static int mark_dynptr_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + int spi; /* For CONST_PTR_TO_DYNPTR, it must have already been done by * check_reg_arg in check_helper_call and mark_btf_func_reg_size in @@ -3220,31 +3403,23 @@ static int mark_dynptr_read(struct bpf_verifier_env *env, struct bpf_reg_state * * bounds and spi is the first dynptr slot. Simply mark stack slot as * read. */ - ret = mark_reg_read(env, &state->stack[spi].spilled_ptr, - state->stack[spi].spilled_ptr.parent, REG_LIVE_READ64); - if (ret) - return ret; - return mark_reg_read(env, &state->stack[spi - 1].spilled_ptr, - state->stack[spi - 1].spilled_ptr.parent, REG_LIVE_READ64); + return mark_stack_slot_obj_read(env, reg, spi, BPF_DYNPTR_NR_SLOTS); } static int mark_iter_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg, int spi, int nr_slots) { - struct bpf_func_state *state = func(env, reg); - int err, i; - - for (i = 0; i < nr_slots; i++) { - struct bpf_reg_state *st = &state->stack[spi - i].spilled_ptr; - - err = mark_reg_read(env, st, st->parent, REG_LIVE_READ64); - if (err) - return err; + return mark_stack_slot_obj_read(env, reg, spi, nr_slots); +} - mark_stack_slot_scratched(env, spi - i); - } +static int mark_irq_flag_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + int spi; - return 0; + spi = irq_flag_get_spi(env, reg); + if (spi < 0) + return spi; + return mark_stack_slot_obj_read(env, reg, spi, 1); } /* This function is supposed to be used by the following 32-bit optimization @@ -4499,7 +4674,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env, int regno) fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN, bt_frame_stack_mask(bt, fr)); verbose(env, "stack=%s: ", env->tmp_str_buf); - print_verifier_state(env, func, true); + print_verifier_state(env, st, fr, true); } } @@ -5496,7 +5671,7 @@ static bool in_sleepable(struct bpf_verifier_env *env) static bool in_rcu_cs(struct bpf_verifier_env *env) { return env->cur_state->active_rcu_lock || - cur_func(env)->active_locks || + env->cur_state->active_locks || !in_sleepable(env); } @@ -7850,15 +8025,15 @@ static int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg * Since only one bpf_spin_lock is allowed the checks are simpler than * reg_is_refcounted() logic. The verifier needs to remember only * one spin_lock instead of array of acquired_refs. - * cur_func(env)->active_locks remembers which map value element or allocated + * env->cur_state->active_locks remembers which map value element or allocated * object got locked and clears it after bpf_spin_unlock. */ static int process_spin_lock(struct bpf_verifier_env *env, int regno, bool is_lock) { struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; + struct bpf_verifier_state *cur = env->cur_state; bool is_const = tnum_is_const(reg->var_off); - struct bpf_func_state *cur = cur_func(env); u64 val = reg->var_off.value; struct bpf_map *map = NULL; struct btf *btf = NULL; @@ -7925,7 +8100,7 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, return -EINVAL; } - if (release_lock_state(cur_func(env), REF_TYPE_LOCK, reg->id, ptr)) { + if (release_lock_state(env->cur_state, REF_TYPE_LOCK, reg->id, ptr)) { verbose(env, "bpf_spin_unlock of different lock\n"); return -EINVAL; } @@ -9669,21 +9844,38 @@ static void mark_pkt_end(struct bpf_verifier_state *vstate, int regn, bool range reg->range = AT_PKT_END; } +static int release_reference_nomark(struct bpf_verifier_state *state, int ref_obj_id) +{ + int i; + + for (i = 0; i < state->acquired_refs; i++) { + if (state->refs[i].type != REF_TYPE_PTR) + continue; + if (state->refs[i].id == ref_obj_id) { + release_reference_state(state, i); + return 0; + } + } + return -EINVAL; +} + /* The pointer with the specified id has released its reference to kernel * resources. Identify all copies of the same pointer and clear the reference. + * + * This is the release function corresponding to acquire_reference(). Idempotent. */ -static int release_reference(struct bpf_verifier_env *env, - int ref_obj_id) +static int release_reference(struct bpf_verifier_env *env, int ref_obj_id) { + struct bpf_verifier_state *vstate = env->cur_state; struct bpf_func_state *state; struct bpf_reg_state *reg; int err; - err = release_reference_state(cur_func(env), ref_obj_id); + err = release_reference_nomark(vstate, ref_obj_id); if (err) return err; - bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({ + bpf_for_each_reg_in_vstate(vstate, state, reg, ({ if (reg->ref_obj_id == ref_obj_id) mark_reg_invalid(env, reg); })); @@ -9757,9 +9949,7 @@ static int setup_func_entry(struct bpf_verifier_env *env, int subprog, int calls callsite, state->curframe + 1 /* frameno within this callchain */, subprog /* subprog number within this prog */); - /* Transfer references to the callee */ - err = copy_reference_state(callee, caller); - err = err ?: set_callee_state_cb(env, caller, callee, callsite); + err = set_callee_state_cb(env, caller, callee, callsite); if (err) goto err_out; @@ -9992,19 +10182,25 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, const char *sub_name = subprog_name(env, subprog); /* Only global subprogs cannot be called with a lock held. */ - if (cur_func(env)->active_locks) { + if (env->cur_state->active_locks) { verbose(env, "global function calls are not allowed while holding a lock,\n" "use static function instead\n"); return -EINVAL; } /* Only global subprogs cannot be called with preemption disabled. */ - if (env->cur_state->active_preempt_lock) { + if (env->cur_state->active_preempt_locks) { verbose(env, "global function calls are not allowed with preemption disabled,\n" "use static function instead\n"); return -EINVAL; } + if (env->cur_state->active_irq_id) { + verbose(env, "global function calls are not allowed with IRQs disabled,\n" + "use static function instead\n"); + return -EINVAL; + } + if (err) { verbose(env, "Caller passes invalid args into func#%d ('%s')\n", subprog, sub_name); @@ -10039,9 +10235,9 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, if (env->log.level & BPF_LOG_LEVEL) { verbose(env, "caller:\n"); - print_verifier_state(env, caller, true); + print_verifier_state(env, state, caller->frameno, true); verbose(env, "callee:\n"); - print_verifier_state(env, state->frame[state->curframe], true); + print_verifier_state(env, state, state->curframe, true); } return 0; @@ -10333,11 +10529,6 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx) caller->regs[BPF_REG_0] = *r0; } - /* Transfer references to the caller */ - err = copy_reference_state(caller, callee); - if (err) - return err; - /* for callbacks like bpf_loop or bpf_for_each_map_elem go back to callsite, * there function call logic would reschedule callback visit. If iteration * converges is_state_visited() would prune that visit eventually. @@ -10350,9 +10541,9 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx) if (env->log.level & BPF_LOG_LEVEL) { verbose(env, "returning from callee:\n"); - print_verifier_state(env, callee, true); + print_verifier_state(env, state, callee->frameno, true); verbose(env, "to caller at %d:\n", *insn_idx); - print_verifier_state(env, caller, true); + print_verifier_state(env, state, caller->frameno, true); } /* clear everything in the callee. In case of exceptional exits using * bpf_throw, this will be done by copy_verifier_state for extra frames. */ @@ -10502,11 +10693,11 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta, static int check_reference_leak(struct bpf_verifier_env *env, bool exception_exit) { - struct bpf_func_state *state = cur_func(env); + struct bpf_verifier_state *state = env->cur_state; bool refs_lingering = false; int i; - if (!exception_exit && state->frameno) + if (!exception_exit && cur_func(env)->frameno) return 0; for (i = 0; i < state->acquired_refs; i++) { @@ -10523,7 +10714,7 @@ static int check_resource_leak(struct bpf_verifier_env *env, bool exception_exit { int err; - if (check_lock && cur_func(env)->active_locks) { + if (check_lock && env->cur_state->active_locks) { verbose(env, "%s cannot be used inside bpf_spin_lock-ed region\n", prefix); return -EINVAL; } @@ -10534,12 +10725,17 @@ static int check_resource_leak(struct bpf_verifier_env *env, bool exception_exit return err; } + if (check_lock && env->cur_state->active_irq_id) { + verbose(env, "%s cannot be used inside bpf_local_irq_save-ed region\n", prefix); + return -EINVAL; + } + if (check_lock && env->cur_state->active_rcu_lock) { verbose(env, "%s cannot be used inside bpf_rcu_read_lock-ed region\n", prefix); return -EINVAL; } - if (check_lock && env->cur_state->active_preempt_lock) { + if (check_lock && env->cur_state->active_preempt_locks) { verbose(env, "%s cannot be used inside bpf_preempt_disable-ed region\n", prefix); return -EINVAL; } @@ -10727,7 +10923,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn env->insn_aux_data[insn_idx].storage_get_func_atomic = true; } - if (env->cur_state->active_preempt_lock) { + if (env->cur_state->active_preempt_locks) { if (fn->might_sleep) { verbose(env, "sleepable helper %s#%d in non-preemptible region\n", func_id_name(func_id), func_id); @@ -10738,6 +10934,17 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn env->insn_aux_data[insn_idx].storage_get_func_atomic = true; } + if (env->cur_state->active_irq_id) { + if (fn->might_sleep) { + verbose(env, "sleepable helper %s#%d in IRQ-disabled region\n", + func_id_name(func_id), func_id); + return -EINVAL; + } + + if (in_sleepable(env) && is_storage_get_function(func_id)) + env->insn_aux_data[insn_idx].storage_get_func_atomic = true; + } + meta.func_id = func_id; /* check args */ for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { @@ -10784,7 +10991,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn struct bpf_func_state *state; struct bpf_reg_state *reg; - err = release_reference_state(cur_func(env), ref_obj_id); + err = release_reference_nomark(env->cur_state, ref_obj_id); if (!err) { bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({ if (reg->ref_obj_id == ref_obj_id) { @@ -11117,7 +11324,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn /* For release_reference() */ regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id; } else if (is_acquire_function(func_id, meta.map_ptr)) { - int id = acquire_reference_state(env, insn_idx); + int id = acquire_reference(env, insn_idx); if (id < 0) return id; @@ -11299,6 +11506,11 @@ static bool is_kfunc_arg_const_str(const struct btf *btf, const struct btf_param return btf_param_match_suffix(btf, arg, "__str"); } +static bool is_kfunc_arg_irq_flag(const struct btf *btf, const struct btf_param *arg) +{ + return btf_param_match_suffix(btf, arg, "__irq_flag"); +} + static bool is_kfunc_arg_scalar_with_name(const struct btf *btf, const struct btf_param *arg, const char *name) @@ -11452,6 +11664,7 @@ enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_CONST_STR, KF_ARG_PTR_TO_MAP, KF_ARG_PTR_TO_WORKQUEUE, + KF_ARG_PTR_TO_IRQ_FLAG, }; enum special_kfunc_type { @@ -11483,6 +11696,8 @@ enum special_kfunc_type { KF_bpf_iter_css_task_new, KF_bpf_session_cookie, KF_bpf_get_kmem_cache, + KF_bpf_local_irq_save, + KF_bpf_local_irq_restore, }; BTF_SET_START(special_kfunc_set) @@ -11549,6 +11764,8 @@ BTF_ID(func, bpf_session_cookie) BTF_ID_UNUSED #endif BTF_ID(func, bpf_get_kmem_cache) +BTF_ID(func, bpf_local_irq_save) +BTF_ID(func, bpf_local_irq_restore) static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta) { @@ -11639,6 +11856,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (is_kfunc_arg_wq(meta->btf, &args[argno])) return KF_ARG_PTR_TO_WORKQUEUE; + if (is_kfunc_arg_irq_flag(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_IRQ_FLAG; + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { if (!btf_type_is_struct(ref_t)) { verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", @@ -11742,11 +11962,59 @@ static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env, return 0; } +static int process_irq_flag(struct bpf_verifier_env *env, int regno, + struct bpf_kfunc_call_arg_meta *meta) +{ + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; + bool irq_save; + int err; + + if (meta->func_id == special_kfunc_list[KF_bpf_local_irq_save]) { + irq_save = true; + } else if (meta->func_id == special_kfunc_list[KF_bpf_local_irq_restore]) { + irq_save = false; + } else { + verbose(env, "verifier internal error: unknown irq flags kfunc\n"); + return -EFAULT; + } + + if (irq_save) { + if (!is_irq_flag_reg_valid_uninit(env, reg)) { + verbose(env, "expected uninitialized irq flag as arg#%d\n", regno - 1); + return -EINVAL; + } + + err = check_mem_access(env, env->insn_idx, regno, 0, BPF_DW, BPF_WRITE, -1, false, false); + if (err) + return err; + + err = mark_stack_slot_irq_flag(env, meta, reg, env->insn_idx); + if (err) + return err; + } else { + err = is_irq_flag_reg_valid_init(env, reg); + if (err) { + verbose(env, "expected an initialized irq flag as arg#%d\n", regno - 1); + return err; + } + + err = mark_irq_flag_read(env, reg); + if (err) + return err; + + err = unmark_stack_slot_irq_flag(env, reg); + if (err) + return err; + } + return 0; +} + + static int ref_set_non_owning(struct bpf_verifier_env *env, struct bpf_reg_state *reg) { struct btf_record *rec = reg_btf_record(reg); - if (!cur_func(env)->active_locks) { + if (!env->cur_state->active_locks) { verbose(env, "verifier internal error: ref_set_non_owning w/o active lock\n"); return -EFAULT; } @@ -11765,12 +12033,11 @@ static int ref_set_non_owning(struct bpf_verifier_env *env, struct bpf_reg_state static int ref_convert_owning_non_owning(struct bpf_verifier_env *env, u32 ref_obj_id) { - struct bpf_func_state *state, *unused; + struct bpf_verifier_state *state = env->cur_state; + struct bpf_func_state *unused; struct bpf_reg_state *reg; int i; - state = cur_func(env); - if (!ref_obj_id) { verbose(env, "verifier internal error: ref_obj_id is zero for " "owning -> non-owning conversion\n"); @@ -11860,9 +12127,9 @@ static int check_reg_allocation_locked(struct bpf_verifier_env *env, struct bpf_ } id = reg->id; - if (!cur_func(env)->active_locks) + if (!env->cur_state->active_locks) return -EINVAL; - s = find_lock_state(env, REF_TYPE_LOCK, id, ptr); + s = find_lock_state(env->cur_state, REF_TYPE_LOCK, id, ptr); if (!s) { verbose(env, "held lock and object are not in the same allocation\n"); return -EINVAL; @@ -12331,6 +12598,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_REFCOUNTED_KPTR: case KF_ARG_PTR_TO_CONST_STR: case KF_ARG_PTR_TO_WORKQUEUE: + case KF_ARG_PTR_TO_IRQ_FLAG: break; default: WARN_ON_ONCE(1); @@ -12625,6 +12893,15 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ if (ret < 0) return ret; break; + case KF_ARG_PTR_TO_IRQ_FLAG: + if (reg->type != PTR_TO_STACK) { + verbose(env, "arg#%d doesn't point to an irq flag on stack\n", i); + return -EINVAL; + } + ret = process_irq_flag(env, regno, meta); + if (ret < 0) + return ret; + break; } } @@ -12789,22 +13066,27 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, return -EINVAL; } - if (env->cur_state->active_preempt_lock) { + if (env->cur_state->active_preempt_locks) { if (preempt_disable) { - env->cur_state->active_preempt_lock++; + env->cur_state->active_preempt_locks++; } else if (preempt_enable) { - env->cur_state->active_preempt_lock--; + env->cur_state->active_preempt_locks--; } else if (sleepable) { verbose(env, "kernel func %s is sleepable within non-preemptible region\n", func_name); return -EACCES; } } else if (preempt_disable) { - env->cur_state->active_preempt_lock++; + env->cur_state->active_preempt_locks++; } else if (preempt_enable) { verbose(env, "unmatched attempt to enable preemption (kernel function %s)\n", func_name); return -EINVAL; } + if (env->cur_state->active_irq_id && sleepable) { + verbose(env, "kernel func %s is sleepable within IRQ-disabled region\n", func_name); + return -EACCES; + } + /* In case of release function, we get register number of refcounted * PTR_TO_BTF_ID in bpf_kfunc_arg_meta, do the release now. */ @@ -13098,7 +13380,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *)); if (is_kfunc_acquire(&meta)) { - int id = acquire_reference_state(env, insn_idx); + int id = acquire_reference(env, insn_idx); if (id < 0) return id; @@ -14495,12 +14777,12 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env, /* Got here implies adding two SCALAR_VALUEs */ if (WARN_ON_ONCE(ptr_reg)) { - print_verifier_state(env, state, true); + print_verifier_state(env, vstate, vstate->curframe, true); verbose(env, "verifier internal error: unexpected ptr_reg\n"); return -EINVAL; } if (WARN_ON(!src_reg)) { - print_verifier_state(env, state, true); + print_verifier_state(env, vstate, vstate->curframe, true); verbose(env, "verifier internal error: no src_reg\n"); return -EINVAL; } @@ -15398,7 +15680,7 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno, * No one could have freed the reference state before * doing the NULL check. */ - WARN_ON_ONCE(release_reference_state(state, id)); + WARN_ON_ONCE(release_reference_nomark(vstate, id)); bpf_for_each_reg_in_vstate(vstate, state, reg, ({ mark_ptr_or_null_reg(state, reg, id, is_null); @@ -15708,7 +15990,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, *insn_idx)) return -EFAULT; if (env->log.level & BPF_LOG_LEVEL) - print_insn_state(env, this_branch->frame[this_branch->curframe]); + print_insn_state(env, this_branch, this_branch->curframe); *insn_idx += insn->off; return 0; } else if (pred == 0) { @@ -15722,7 +16004,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, *insn_idx)) return -EFAULT; if (env->log.level & BPF_LOG_LEVEL) - print_insn_state(env, this_branch->frame[this_branch->curframe]); + print_insn_state(env, this_branch, this_branch->curframe); return 0; } @@ -15839,7 +16121,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env, return -EACCES; } if (env->log.level & BPF_LOG_LEVEL) - print_insn_state(env, this_branch->frame[this_branch->curframe]); + print_insn_state(env, this_branch, this_branch->curframe); return 0; } @@ -17738,6 +18020,12 @@ static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, !check_ids(old_reg->ref_obj_id, cur_reg->ref_obj_id, idmap)) return false; break; + case STACK_IRQ_FLAG: + old_reg = &old->stack[spi].spilled_ptr; + cur_reg = &cur->stack[spi].spilled_ptr; + if (!check_ids(old_reg->ref_obj_id, cur_reg->ref_obj_id, idmap)) + return false; + break; case STACK_MISC: case STACK_ZERO: case STACK_INVALID: @@ -17750,7 +18038,7 @@ static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, return true; } -static bool refsafe(struct bpf_func_state *old, struct bpf_func_state *cur, +static bool refsafe(struct bpf_verifier_state *old, struct bpf_verifier_state *cur, struct bpf_idmap *idmap) { int i; @@ -17758,12 +18046,25 @@ static bool refsafe(struct bpf_func_state *old, struct bpf_func_state *cur, if (old->acquired_refs != cur->acquired_refs) return false; + if (old->active_locks != cur->active_locks) + return false; + + if (old->active_preempt_locks != cur->active_preempt_locks) + return false; + + if (old->active_rcu_lock != cur->active_rcu_lock) + return false; + + if (!check_ids(old->active_irq_id, cur->active_irq_id, idmap)) + return false; + for (i = 0; i < old->acquired_refs; i++) { if (!check_ids(old->refs[i].id, cur->refs[i].id, idmap) || old->refs[i].type != cur->refs[i].type) return false; switch (old->refs[i].type) { case REF_TYPE_PTR: + case REF_TYPE_IRQ: break; case REF_TYPE_LOCK: if (old->refs[i].ptr != cur->refs[i].ptr) @@ -17820,9 +18121,6 @@ static bool func_states_equal(struct bpf_verifier_env *env, struct bpf_func_stat if (!stacksafe(env, old, cur, &env->idmap_scratch, exact)) return false; - if (!refsafe(old, cur, &env->idmap_scratch)) - return false; - return true; } @@ -17850,13 +18148,10 @@ static bool states_equal(struct bpf_verifier_env *env, if (old->speculative && !cur->speculative) return false; - if (old->active_rcu_lock != cur->active_rcu_lock) - return false; - - if (old->active_preempt_lock != cur->active_preempt_lock) + if (old->in_sleepable != cur->in_sleepable) return false; - if (old->in_sleepable != cur->in_sleepable) + if (!refsafe(old, cur, &env->idmap_scratch)) return false; /* for states to be equal callsites have to be the same @@ -18249,9 +18544,9 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) verbose_linfo(env, insn_idx, "; "); verbose(env, "infinite loop detected at insn %d\n", insn_idx); verbose(env, "cur state:"); - print_verifier_state(env, cur->frame[cur->curframe], true); + print_verifier_state(env, cur, cur->curframe, true); verbose(env, "old state:"); - print_verifier_state(env, sl->state.frame[cur->curframe], true); + print_verifier_state(env, &sl->state, cur->curframe, true); return -EINVAL; } /* if the verifier is processing a loop, avoid adding new state @@ -18607,7 +18902,7 @@ static int do_check(struct bpf_verifier_env *env) env->prev_insn_idx, env->insn_idx, env->cur_state->speculative ? " (speculative execution)" : ""); - print_verifier_state(env, state->frame[state->curframe], true); + print_verifier_state(env, state, state->curframe, true); do_print_state = false; } @@ -18619,7 +18914,7 @@ static int do_check(struct bpf_verifier_env *env) }; if (verifier_state_scratched(env)) - print_insn_state(env, state->frame[state->curframe]); + print_insn_state(env, state, state->curframe); verbose_linfo(env, env->insn_idx, "; "); env->prev_log_pos = env->log.end_pos; @@ -18751,7 +19046,7 @@ static int do_check(struct bpf_verifier_env *env) return -EINVAL; } - if (cur_func(env)->active_locks) { + if (env->cur_state->active_locks) { if ((insn->src_reg == BPF_REG_0 && insn->imm != BPF_FUNC_spin_unlock) || (insn->src_reg == BPF_PSEUDO_KFUNC_CALL && (insn->off != 0 || !is_bpf_graph_api_kfunc(insn->imm)))) { @@ -18807,7 +19102,7 @@ process_bpf_exit_full: * match caller reference state when it exits. */ err = check_resource_leak(env, exception_exit, !env->cur_state->curframe, - "BPF_EXIT instruction"); + "BPF_EXIT instruction in main prog"); if (err) return err; |
