diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1c6863ce89e0..d1a17c118316 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1062,7 +1062,7 @@ struct bpf_insn_access_aux { struct { struct btf *btf; u32 btf_id; - u32 ref_obj_id; + u32 ref_id; }; }; struct bpf_verifier_log *log; /* for verbose logs */ @@ -1631,7 +1631,7 @@ struct bpf_ctx_arg_aux { enum bpf_reg_type reg_type; struct btf *btf; u32 btf_id; - u32 ref_obj_id; + u32 ref_id; bool refcounted; }; diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 5cbad3b64130..3dd2d21230af 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -66,7 +66,6 @@ struct bpf_reg_state { struct { /* for PTR_TO_MEM | PTR_TO_MEM_OR_NULL */ u32 mem_size; - u32 dynptr_id; /* for dynptr slices */ }; /* For dynptr stack slots */ @@ -148,46 +147,14 @@ struct bpf_reg_state { #define BPF_ADD_CONST32 (1U << 30) #define BPF_ADD_CONST (BPF_ADD_CONST64 | BPF_ADD_CONST32) u32 id; - /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned - * from a pointer-cast helper, bpf_sk_fullsock() and - * bpf_tcp_sock(). - * - * Consider the following where "sk" is a reference counted - * pointer returned from "sk = bpf_sk_lookup_tcp();": - * - * 1: sk = bpf_sk_lookup_tcp(); - * 2: if (!sk) { return 0; } - * 3: fullsock = bpf_sk_fullsock(sk); - * 4: if (!fullsock) { bpf_sk_release(sk); return 0; } - * 5: tp = bpf_tcp_sock(fullsock); - * 6: if (!tp) { bpf_sk_release(sk); return 0; } - * 7: bpf_sk_release(sk); - * 8: snd_cwnd = tp->snd_cwnd; // verifier will complain - * - * After bpf_sk_release(sk) at line 7, both "fullsock" ptr and - * "tp" ptr should be invalidated also. In order to do that, - * the reg holding "fullsock" and "sk" need to remember - * the original refcounted ptr id (i.e. sk_reg->id) in ref_obj_id - * such that the verifier can reset all regs which have - * ref_obj_id matching the sk_reg->id. - * - * sk_reg->ref_obj_id is set to sk_reg->id at line 1. - * sk_reg->id will stay as NULL-marking purpose only. - * After NULL-marking is done, sk_reg->id can be reset to 0. - * - * After "fullsock = bpf_sk_fullsock(sk);" at line 3, - * fullsock_reg->ref_obj_id is set to sk_reg->ref_obj_id. - * - * After "tp = bpf_tcp_sock(fullsock);" at line 5, - * tp_reg->ref_obj_id is set to fullsock_reg->ref_obj_id - * which is the same as sk_reg->ref_obj_id. - * - * From the verifier perspective, if sk, fullsock and tp - * are not NULL, they are the same ptr with different - * reg->type. In particular, bpf_sk_release(tp) is also - * allowed and has the same effect as bpf_sk_release(sk). + /* + * Tracks the parent object this register was derived from. + * Used for cascading invalidation: when the parent object is + * released or invalidated, all registers with matching parent_id + * are also invalidated. For example, a slice from bpf_dynptr_data() + * gets parent_id set to the dynptr's id. */ - u32 ref_obj_id; + u32 parent_id; /* Inside the callee two registers can be both PTR_TO_STACK like * R1=fp-8 and R2=fp-8, but one of them points to this function stack * while another to the caller's stack. To differentiate them 'frameno' @@ -364,10 +331,14 @@ struct bpf_reference_state { * is used purely to inform the user of a reference leak. */ int insn_idx; - /* Use to keep track of the source object of a lock, to ensure - * it matches on unlock. - */ - void *ptr; + union { + /* For REF_TYPE_PTR */ + int parent_id; + /* Use to keep track of the source object of a lock, to ensure + * it matches on unlock. + */ + void *ptr; + }; }; struct bpf_retval_range { @@ -585,7 +556,7 @@ bpf_get_spilled_stack_arg(int slot, struct bpf_func_state *frame) iter < frame->out_stack_arg_cnt; \ iter++, reg = bpf_get_spilled_stack_arg(iter, frame)) -#define bpf_for_each_reg_in_vstate_mask(__vst, __state, __reg, __mask, __expr) \ +#define bpf_for_each_reg_in_vstate_mask(__vst, __state, __reg, __stack, __mask, __expr) \ ({ \ struct bpf_verifier_state *___vstate = __vst; \ int ___i, ___j; \ @@ -593,6 +564,7 @@ bpf_get_spilled_stack_arg(int slot, struct bpf_func_state *frame) struct bpf_reg_state *___regs; \ __state = ___vstate->frame[___i]; \ ___regs = __state->regs; \ + __stack = NULL; \ for (___j = 0; ___j < MAX_BPF_REG; ___j++) { \ __reg = &___regs[___j]; \ (void)(__expr); \ @@ -600,8 +572,10 @@ bpf_get_spilled_stack_arg(int slot, struct bpf_func_state *frame) bpf_for_each_spilled_reg(___j, __state, __reg, __mask) { \ if (!__reg) \ continue; \ + __stack = &__state->stack[___j]; \ (void)(__expr); \ } \ + __stack = NULL; \ bpf_for_each_spilled_stack_arg(___j, __state, __reg) { \ if (!__reg) \ continue; \ @@ -611,8 +585,13 @@ bpf_get_spilled_stack_arg(int slot, struct bpf_func_state *frame) }) /* Invoke __expr over regsiters in __vst, setting __state and __reg */ -#define bpf_for_each_reg_in_vstate(__vst, __state, __reg, __expr) \ - bpf_for_each_reg_in_vstate_mask(__vst, __state, __reg, 1 << STACK_SPILL, __expr) +#define bpf_for_each_reg_in_vstate(__vst, __state, __reg, __expr) \ + ({ \ + struct bpf_stack_state * ___stack; \ + (void)___stack; \ + bpf_for_each_reg_in_vstate_mask(__vst, __state, __reg, ___stack,\ + 1 << STACK_SPILL, __expr); \ + }) /* linked list of verifier states used to prune search */ struct bpf_verifier_state_list { @@ -1438,6 +1417,25 @@ struct bpf_map_desc { int uid; }; +/* The last initialized dynptr; Populated by process_dynptr_func() */ +struct bpf_dynptr_desc { + enum bpf_dynptr_type type; + u32 id; + u32 parent_id; +}; + +/* + * The last seen rereferenced object; Updated by update_ref_obj() when a register refers to a + * referenced object. Used when the helper or kfunc is casting a referenced object, returning + * allocated memory derived from referenced object or creating a dynptr with a referenced + * object as parent. + */ +struct ref_obj_desc { + u32 id; + u32 parent_id; + u8 cnt; +}; + struct bpf_kfunc_call_arg_meta { /* In parameters */ struct btf *btf; @@ -1446,7 +1444,6 @@ struct bpf_kfunc_call_arg_meta { const struct btf_type *func_proto; const char *func_name; /* Out parameters */ - u32 ref_obj_id; u8 release_regno; bool r0_rdonly; u32 ret_btf_id; @@ -1478,16 +1475,13 @@ struct bpf_kfunc_call_arg_meta { struct { struct btf_field *field; } arg_rbtree_root; - struct { - enum bpf_dynptr_type type; - u32 id; - u32 ref_obj_id; - } initialized_dynptr; struct { u8 spi; u8 frameno; } iter; struct bpf_map_desc map; + struct bpf_dynptr_desc dynptr; + struct ref_obj_desc ref_obj; u64 mem_size; }; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 17d4ab0a8206..f429f6f58cb2 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6957,7 +6957,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, info->reg_type = ctx_arg_info->reg_type; info->btf = ctx_arg_info->btf ? : btf_vmlinux; info->btf_id = ctx_arg_info->btf_id; - info->ref_obj_id = ctx_arg_info->ref_obj_id; + info->ref_id = ctx_arg_info->ref_id; return true; } } diff --git a/kernel/bpf/fixups.c b/kernel/bpf/fixups.c index 12739add2dda..5aa3f7d99ac9 100644 --- a/kernel/bpf/fixups.c +++ b/kernel/bpf/fixups.c @@ -870,7 +870,7 @@ int bpf_convert_ctx_accesses(struct bpf_verifier_env *env) case PTR_TO_BTF_ID: case PTR_TO_BTF_ID | PTR_UNTRUSTED: /* PTR_TO_BTF_ID | MEM_ALLOC always has a valid lifetime, unlike - * PTR_TO_BTF_ID, and an active ref_obj_id, but the same cannot + * PTR_TO_BTF_ID, and an active referenced id, but the same cannot * be said once it is marked PTR_UNTRUSTED, hence we must handle * any faults for loads into such types. BPF_WRITE is disallowed * for this case. diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 9ca195104667..03004e4451f5 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -4957,7 +4957,7 @@ BTF_ID_FLAGS(func, bpf_stream_print_stack, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, bpf_task_work_schedule_signal, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, bpf_task_work_schedule_resume, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, bpf_dynptr_from_file) -BTF_ID_FLAGS(func, bpf_dynptr_file_discard) +BTF_ID_FLAGS(func, bpf_dynptr_file_discard, KF_RELEASE) BTF_ID_FLAGS(func, bpf_timer_cancel_async) BTF_KFUNCS_END(common_btf_ids) diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index 62fe6ed18374..b740fa73ee26 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -665,8 +665,8 @@ static void print_reg_state(struct bpf_verifier_env *env, verbose_a("id=%d", reg->id & ~BPF_ADD_CONST); if (reg->id & BPF_ADD_CONST) verbose(env, "%+d", reg->delta); - if (reg->ref_obj_id) - verbose_a("ref_obj_id=%d", reg->ref_obj_id); + if (reg->parent_id) + verbose_a("parent_id=%d", reg->parent_id); if (type_is_non_owning_ref(reg->type)) verbose_a("%s", "non_own_ref"); if (type_is_map_ptr(t)) { @@ -768,21 +768,19 @@ void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_verifie verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type)); if (reg->id) verbose_a("id=%d", reg->id); - if (reg->ref_obj_id) - verbose_a("ref_id=%d", reg->ref_obj_id); - if (reg->dynptr_id) - verbose_a("dynptr_id=%d", reg->dynptr_id); + if (reg->parent_id) + verbose_a("parent_id=%d", reg->parent_id); verbose(env, ")"); break; case STACK_ITER: - /* only main slot has ref_obj_id set; skip others */ - if (!reg->ref_obj_id) + /* only main slot has id set; skip others */ + if (!reg->id) continue; - verbose(env, " fp%d=iter_%s(ref_id=%d,state=%s,depth=%u)", + verbose(env, " fp%d=iter_%s(id=%d,state=%s,depth=%u)", (-i - 1) * BPF_REG_SIZE, iter_type_str(reg->iter.btf, reg->iter.btf_id), - reg->ref_obj_id, iter_state_str(reg->iter.state), + reg->id, iter_state_str(reg->iter.state), reg->iter.depth); break; case STACK_MISC: diff --git a/kernel/bpf/states.c b/kernel/bpf/states.c index 877338136009..5945956a7573 100644 --- a/kernel/bpf/states.c +++ b/kernel/bpf/states.c @@ -489,7 +489,7 @@ static bool regs_exact(const struct bpf_reg_state *rold, { return memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)) == 0 && check_ids(rold->id, rcur->id, idmap) && - check_ids(rold->ref_obj_id, rcur->ref_obj_id, idmap); + check_ids(rold->parent_id, rcur->parent_id, idmap); } enum exact_level { @@ -614,7 +614,7 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold, range_within(rold, rcur) && tnum_in(rold->var_off, rcur->var_off) && check_ids(rold->id, rcur->id, idmap) && - check_ids(rold->ref_obj_id, rcur->ref_obj_id, idmap); + check_ids(rold->parent_id, rcur->parent_id, idmap); case PTR_TO_PACKET_META: case PTR_TO_PACKET: /* We must have at least as much range as the old ptr @@ -794,7 +794,8 @@ static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, cur_reg = &cur->stack[spi].spilled_ptr; if (old_reg->dynptr.type != cur_reg->dynptr.type || old_reg->dynptr.first_slot != cur_reg->dynptr.first_slot || - !check_ids(old_reg->ref_obj_id, cur_reg->ref_obj_id, idmap)) + !check_ids(old_reg->id, cur_reg->id, idmap) || + !check_ids(old_reg->parent_id, cur_reg->parent_id, idmap)) return false; break; case STACK_ITER: @@ -810,13 +811,13 @@ static bool stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, old_reg->iter.btf_id != cur_reg->iter.btf_id || old_reg->iter.state != cur_reg->iter.state || /* ignore {old_reg,cur_reg}->iter.depth, see above */ - !check_ids(old_reg->ref_obj_id, cur_reg->ref_obj_id, idmap)) + !check_ids(old_reg->id, cur_reg->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) || + if (!check_ids(old_reg->id, cur_reg->id, idmap) || old_reg->irq.kfunc_class != cur_reg->irq.kfunc_class) return false; break; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3a270bc485c2..5d8f2656dbfd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -200,14 +200,14 @@ struct bpf_verifier_stack_elem { #define BPF_PRIV_STACK_MIN_SIZE 64 -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 int acquire_reference(struct bpf_verifier_env *env, int insn_idx, int parent_id); +static int release_reference_nomark(struct bpf_verifier_state *state, int id); +static int release_reference(struct bpf_verifier_env *env, int id); static void invalidate_non_owning_refs(struct bpf_verifier_env *env); static bool in_rbtree_lock_required_cb(struct bpf_verifier_env *env); static int ref_set_non_owning(struct bpf_verifier_env *env, struct bpf_reg_state *reg); -static bool is_trusted_reg(const struct bpf_reg_state *reg); +static bool is_trusted_reg(struct bpf_verifier_env *env, const struct bpf_reg_state *reg); static inline bool in_sleepable_context(struct bpf_verifier_env *env); static const char *non_sleepable_context_description(struct bpf_verifier_env *env); static void scalar32_min_max_add(struct bpf_reg_state *dst_reg, struct bpf_reg_state *src_reg); @@ -231,8 +231,28 @@ static void bpf_map_key_store(struct bpf_insn_aux_data *aux, u64 state) (poisoned ? BPF_MAP_KEY_POISON : 0ULL); } +static void update_ref_obj(struct ref_obj_desc *ref_obj, struct bpf_reg_state *reg) +{ + ref_obj->id = reg->id; + ref_obj->parent_id = reg->parent_id; + ref_obj->cnt++; +} + +static int validate_ref_obj(struct bpf_verifier_env *env, struct ref_obj_desc *ref_obj) +{ + if (ref_obj->cnt > 1) { + verifier_bug(env, "function expects only one referenced object but got %d\n", + ref_obj->cnt); + return -EFAULT; + } + + return 0; +} + struct bpf_call_arg_meta { struct bpf_map_desc map; + struct bpf_dynptr_desc dynptr; + struct ref_obj_desc ref_obj; bool raw_mode; bool pkt_access; u8 release_regno; @@ -240,8 +260,6 @@ struct bpf_call_arg_meta { int access_size; int mem_size; u64 msize_max_value; - int ref_obj_id; - int dynptr_id; int func_id; struct btf *btf; u32 btf_id; @@ -339,7 +357,7 @@ static void verbose_invalid_scalar(struct bpf_verifier_env *env, verbose(env, " should have been in [%d, %d]\n", range.minval, range.maxval); } -static bool reg_not_null(const struct bpf_reg_state *reg) +static bool reg_not_null(struct bpf_verifier_env *env, const struct bpf_reg_state *reg) { enum bpf_reg_type type; @@ -353,7 +371,7 @@ static bool reg_not_null(const struct bpf_reg_state *reg) type == PTR_TO_MAP_VALUE || type == PTR_TO_MAP_KEY || type == PTR_TO_SOCK_COMMON || - (type == PTR_TO_BTF_ID && is_trusted_reg(reg)) || + (type == PTR_TO_BTF_ID && is_trusted_reg(env, reg)) || (type == PTR_TO_MEM && !(reg->type & PTR_UNTRUSTED)) || type == CONST_PTR_TO_MAP; } @@ -470,11 +488,6 @@ static bool is_ptr_cast_function(enum bpf_func_id func_id) func_id == BPF_FUNC_skc_to_tcp_request_sock; } -static bool is_dynptr_ref_function(enum bpf_func_id func_id) -{ - return func_id == BPF_FUNC_dynptr_data; -} - static bool is_sync_callback_calling_kfunc(u32 btf_id); static bool is_async_callback_calling_kfunc(u32 btf_id); static bool is_callback_calling_kfunc(u32 btf_id); @@ -533,22 +546,6 @@ bool bpf_is_may_goto_insn(struct bpf_insn *insn) return insn->code == (BPF_JMP | BPF_JCOND) && insn->src_reg == BPF_MAY_GOTO; } -static bool helper_multiple_ref_obj_use(enum bpf_func_id func_id, - const struct bpf_map *map) -{ - int ref_obj_uses = 0; - - if (is_ptr_cast_function(func_id)) - ref_obj_uses++; - if (is_acquire_function(func_id, map)) - ref_obj_uses++; - if (is_dynptr_ref_function(func_id)) - ref_obj_uses++; - - return ref_obj_uses > 1; -} - - static bool is_spi_bounds_valid(struct bpf_func_state *state, int spi, int nr_slots) { int allocated_slots = state->allocated_stack / BPF_REG_SIZE; @@ -645,43 +642,44 @@ static enum bpf_type_flag get_dynptr_type_flag(enum bpf_dynptr_type type) } } -static bool dynptr_type_refcounted(enum bpf_dynptr_type type) +static bool dynptr_type_referenced(enum bpf_dynptr_type type) { return type == BPF_DYNPTR_TYPE_RINGBUF || type == BPF_DYNPTR_TYPE_FILE; } static void __mark_dynptr_reg(struct bpf_reg_state *reg, enum bpf_dynptr_type type, - bool first_slot, int dynptr_id); + bool first_slot, int id, int parent_id); static void mark_dynptr_stack_regs(struct bpf_verifier_env *env, struct bpf_reg_state *sreg1, struct bpf_reg_state *sreg2, - enum bpf_dynptr_type type) + enum bpf_dynptr_type type, int parent_id) { int id = ++env->id_gen; - __mark_dynptr_reg(sreg1, type, true, id); - __mark_dynptr_reg(sreg2, type, false, id); + __mark_dynptr_reg(sreg1, type, true, id, parent_id); + __mark_dynptr_reg(sreg2, type, false, id, parent_id); } static void mark_dynptr_cb_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, enum bpf_dynptr_type type) { - __mark_dynptr_reg(reg, type, true, ++env->id_gen); + __mark_dynptr_reg(reg, type, true, ++env->id_gen, 0); } static int destroy_if_dynptr_stack_slot(struct bpf_verifier_env *env, struct bpf_func_state *state, int spi); static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_state *reg, - enum bpf_arg_type arg_type, int insn_idx, int clone_ref_obj_id) + enum bpf_arg_type arg_type, int insn_idx, + struct ref_obj_desc *ref_obj, struct bpf_dynptr_desc *dynptr) { struct bpf_func_state *state = bpf_func(env, reg); + int spi, i, err, parent_id = 0; enum bpf_dynptr_type type; - int spi, i, err; spi = dynptr_get_spi(env, reg); if (spi < 0) @@ -712,85 +710,69 @@ static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_ if (type == BPF_DYNPTR_TYPE_INVALID) return -EINVAL; - mark_dynptr_stack_regs(env, &state->stack[spi].spilled_ptr, - &state->stack[spi - 1].spilled_ptr, type); + if (dynptr->type == BPF_DYNPTR_TYPE_INVALID) { /* dynptr constructors */ + err = validate_ref_obj(env, ref_obj); + if (err) + return err; - if (dynptr_type_refcounted(type)) { - /* The id is used to track proper releasing */ - int id; + /* Track parent's id if the parent is a referenced object */ + parent_id = ref_obj->id; - if (clone_ref_obj_id) - id = clone_ref_obj_id; - else - id = acquire_reference(env, insn_idx); + if (dynptr_type_referenced(type)) { + int id; - if (id < 0) - return id; + /* + * Create an intermediate reference that tracks the referenced + * object for the referenced dynptr. Freeing a referenced dynptr + * through helpers/kfuncs will invalidate all clones. + */ + id = acquire_reference(env, insn_idx, parent_id); + if (id < 0) + return id; - state->stack[spi].spilled_ptr.ref_obj_id = id; - state->stack[spi - 1].spilled_ptr.ref_obj_id = id; + parent_id = id; + } + } else { /* bpf_dynptr_clone() */ + parent_id = dynptr->parent_id; } + mark_dynptr_stack_regs(env, &state->stack[spi].spilled_ptr, + &state->stack[spi - 1].spilled_ptr, type, parent_id); + return 0; } -static void invalidate_dynptr(struct bpf_verifier_env *env, struct bpf_func_state *state, int spi) +static void invalidate_dynptr(struct bpf_verifier_env *env, struct bpf_stack_state *stack) { int i; for (i = 0; i < BPF_REG_SIZE; i++) { - state->stack[spi].slot_type[i] = STACK_INVALID; - state->stack[spi - 1].slot_type[i] = STACK_INVALID; + stack[0].slot_type[i] = STACK_INVALID; + stack[1].slot_type[i] = STACK_INVALID; } - bpf_mark_reg_not_init(env, &state->stack[spi].spilled_ptr); - bpf_mark_reg_not_init(env, &state->stack[spi - 1].spilled_ptr); + bpf_mark_reg_not_init(env, &stack[0].spilled_ptr); + bpf_mark_reg_not_init(env, &stack[1].spilled_ptr); } static int unmark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_state *reg) { struct bpf_func_state *state = bpf_func(env, reg); - int spi, ref_obj_id, i; + int spi; spi = dynptr_get_spi(env, reg); if (spi < 0) return spi; - if (!dynptr_type_refcounted(state->stack[spi].spilled_ptr.dynptr.type)) { - invalidate_dynptr(env, state, spi); - return 0; - } - - ref_obj_id = state->stack[spi].spilled_ptr.ref_obj_id; - - /* If the dynptr has a ref_obj_id, then we need to invalidate - * two things: - * - * 1) Any dynptrs with a matching ref_obj_id (clones) - * 2) Any slices derived from this dynptr. + /* + * For referenced dynptr, release the parent ref which cascades to + * all clones and derived slices. For non-referenced dynptr, only + * the dynptr and slices derived from it will be invalidated. */ - - /* Invalidate any slices associated with this dynptr */ - WARN_ON_ONCE(release_reference(env, ref_obj_id)); - - /* Invalidate any dynptr clones */ - for (i = 1; i < state->allocated_stack / BPF_REG_SIZE; i++) { - if (state->stack[i].spilled_ptr.ref_obj_id != ref_obj_id) - continue; - - /* it should always be the case that if the ref obj id - * matches then the stack slot also belongs to a - * dynptr - */ - if (state->stack[i].slot_type[0] != STACK_DYNPTR) { - verifier_bug(env, "misconfigured ref_obj_id"); - return -EFAULT; - } - if (state->stack[i].spilled_ptr.dynptr.first_slot) - invalidate_dynptr(env, state, i); - } - - return 0; + reg = &state->stack[spi].spilled_ptr; + return release_reference(env, dynptr_type_referenced(reg->dynptr.type) + ? reg->parent_id + : reg->id); } static void __mark_reg_unknown(const struct bpf_verifier_env *env, @@ -804,12 +786,29 @@ static void mark_reg_invalid(const struct bpf_verifier_env *env, struct bpf_reg_ __mark_reg_unknown(env, reg); } +static int dynptr_ref_cnt(struct bpf_verifier_env *env, int v_parent_id) +{ + struct bpf_stack_state *stack; + struct bpf_func_state *state; + struct bpf_reg_state *reg; + int ref_cnt = 0; + + bpf_for_each_reg_in_vstate_mask(env->cur_state, state, reg, stack, 1 << STACK_DYNPTR, ({ + if (!stack || stack->slot_type[0] != STACK_DYNPTR) + continue; + if (!stack->spilled_ptr.dynptr.first_slot) + continue; + if (stack->spilled_ptr.parent_id == v_parent_id) + ref_cnt++; + })); + + return ref_cnt; +} + static int destroy_if_dynptr_stack_slot(struct bpf_verifier_env *env, struct bpf_func_state *state, int spi) { - struct bpf_func_state *fstate; - struct bpf_reg_state *dreg; - int i, dynptr_id; + int err = 0; /* We always ensure that STACK_DYNPTR is never set partially, * hence just checking for slot_type[0] is enough. This is @@ -823,56 +822,25 @@ static int destroy_if_dynptr_stack_slot(struct bpf_verifier_env *env, if (!state->stack[spi].spilled_ptr.dynptr.first_slot) spi = spi + 1; - if (dynptr_type_refcounted(state->stack[spi].spilled_ptr.dynptr.type)) { - int ref_obj_id = state->stack[spi].spilled_ptr.ref_obj_id; - int ref_cnt = 0; - - /* - * A referenced dynptr can be overwritten only if there is at - * least one other dynptr sharing the same ref_obj_id, - * ensuring the reference can still be properly released. - */ - for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { - if (state->stack[i].slot_type[0] != STACK_DYNPTR) - continue; - if (!state->stack[i].spilled_ptr.dynptr.first_slot) - continue; - if (state->stack[i].spilled_ptr.ref_obj_id == ref_obj_id) - ref_cnt++; - } - - if (ref_cnt <= 1) { - verbose(env, "cannot overwrite referenced dynptr\n"); - return -EINVAL; - } - } - - mark_stack_slot_scratched(env, spi); - mark_stack_slot_scratched(env, spi - 1); - - /* Writing partially to one dynptr stack slot destroys both. */ - for (i = 0; i < BPF_REG_SIZE; i++) { - state->stack[spi].slot_type[i] = STACK_INVALID; - state->stack[spi - 1].slot_type[i] = STACK_INVALID; - } - - dynptr_id = state->stack[spi].spilled_ptr.id; - /* Invalidate any slices associated with this dynptr */ - bpf_for_each_reg_in_vstate(env->cur_state, fstate, dreg, ({ - /* Dynptr slices are only PTR_TO_MEM_OR_NULL and PTR_TO_MEM */ - if (dreg->type != (PTR_TO_MEM | PTR_MAYBE_NULL) && dreg->type != PTR_TO_MEM) - continue; - if (dreg->dynptr_id == dynptr_id) - mark_reg_invalid(env, dreg); - })); - - /* Do not release reference state, we are destroying dynptr on stack, - * not using some helper to release it. Just reset register. + /* + * A referenced dynptr can be overwritten only if there is at + * least one other dynptr sharing the same virtual ref parent, + * ensuring the reference can still be properly released. */ - bpf_mark_reg_not_init(env, &state->stack[spi].spilled_ptr); - bpf_mark_reg_not_init(env, &state->stack[spi - 1].spilled_ptr); + if (dynptr_type_referenced(state->stack[spi].spilled_ptr.dynptr.type) && + dynptr_ref_cnt(env, state->stack[spi].spilled_ptr.parent_id) <= 1) { + verbose(env, "cannot overwrite referenced dynptr\n"); + return -EINVAL; + } - return 0; + /* Invalidate the dynptr and any derived slices */ + err = release_reference(env, state->stack[spi].spilled_ptr.id); + if (!err) { + mark_stack_slot_scratched(env, spi); + mark_stack_slot_scratched(env, spi - 1); + } + + return err; } static bool is_dynptr_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_reg_state *reg) @@ -972,7 +940,7 @@ static int mark_stack_slots_iter(struct bpf_verifier_env *env, if (spi < 0) return spi; - id = acquire_reference(env, insn_idx); + id = acquire_reference(env, insn_idx, 0); if (id < 0) return id; @@ -988,7 +956,7 @@ static int mark_stack_slots_iter(struct bpf_verifier_env *env, else st->type |= PTR_UNTRUSTED; } - st->ref_obj_id = i == 0 ? id : 0; + st->id = i == 0 ? id : 0; st->iter.btf = btf; st->iter.btf_id = btf_id; st->iter.state = BPF_ITER_STATE_ACTIVE; @@ -1018,7 +986,7 @@ static int unmark_stack_slots_iter(struct bpf_verifier_env *env, struct bpf_reg_state *st = &slot->spilled_ptr; if (i == 0) - WARN_ON_ONCE(release_reference(env, st->ref_obj_id)); + WARN_ON_ONCE(release_reference(env, st->id)); bpf_mark_reg_not_init(env, st); @@ -1074,10 +1042,10 @@ static int is_iter_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_s if (st->type & PTR_UNTRUSTED) return -EPROTO; - /* only main (first) slot has ref_obj_id set */ - if (i == 0 && !st->ref_obj_id) + /* only main (first) slot has id set */ + if (i == 0 && !st->id) return -EINVAL; - if (i != 0 && st->ref_obj_id) + if (i != 0 && st->id) return -EINVAL; if (st->iter.btf != btf || st->iter.btf_id != btf_id) return -EINVAL; @@ -1116,7 +1084,7 @@ static int mark_stack_slot_irq_flag(struct bpf_verifier_env *env, __mark_reg_known_zero(st); st->type = PTR_TO_STACK; /* we don't have dedicated reg type */ - st->ref_obj_id = id; + st->id = id; st->irq.kfunc_class = kfunc_class; for (i = 0; i < BPF_REG_SIZE; i++) @@ -1150,7 +1118,7 @@ static int unmark_stack_slot_irq_flag(struct bpf_verifier_env *env, struct bpf_r return -EINVAL; } - err = release_irq_state(env->cur_state, st->ref_obj_id); + err = release_irq_state(env->cur_state, st->id); WARN_ON_ONCE(err && err != -EACCES); if (err) { int insn_idx = 0; @@ -1214,7 +1182,7 @@ static int is_irq_flag_reg_valid_init(struct bpf_verifier_env *env, struct bpf_r slot = &state->stack[spi]; st = &slot->spilled_ptr; - if (!st->ref_obj_id) + if (!st->id) return -EINVAL; for (i = 0; i < BPF_REG_SIZE; i++) @@ -1455,7 +1423,7 @@ static struct bpf_reference_state *acquire_reference_state(struct bpf_verifier_e return &state->refs[new_ofs]; } -static int acquire_reference(struct bpf_verifier_env *env, int insn_idx) +static int acquire_reference(struct bpf_verifier_env *env, int insn_idx, int parent_id) { struct bpf_reference_state *s; @@ -1464,6 +1432,7 @@ static int acquire_reference(struct bpf_verifier_env *env, int insn_idx) return -ENOMEM; s->type = REF_TYPE_PTR; s->id = ++env->id_gen; + s->parent_id = parent_id; return s->id; } @@ -1520,17 +1489,25 @@ static void release_reference_state(struct bpf_verifier_state *state, int idx) return; } -static bool find_reference_state(struct bpf_verifier_state *state, int ptr_id) +static bool find_reference_state(struct bpf_verifier_state *state, int id) { int i; - for (i = 0; i < state->acquired_refs; i++) - if (state->refs[i].id == ptr_id) + for (i = 0; i < state->acquired_refs; i++) { + if (state->refs[i].type != REF_TYPE_PTR) + continue; + if (state->refs[i].id == id) return true; + } return false; } +static bool reg_is_referenced(struct bpf_verifier_env *env, const struct bpf_reg_state *reg) +{ + return find_reference_state(env->cur_state, reg->id); +} + static int release_lock_state(struct bpf_verifier_state *state, int type, int id, void *ptr) { void *prev_ptr = NULL; @@ -1844,7 +1821,7 @@ static void __mark_reg_known(struct bpf_reg_state *reg, u64 imm) memset(((u8 *)reg) + sizeof(reg->type), 0, offsetof(struct bpf_reg_state, var_off) - sizeof(reg->type)); reg->id = 0; - reg->ref_obj_id = 0; + reg->parent_id = 0; ___mark_reg_known(reg, imm); } @@ -1879,7 +1856,7 @@ static void mark_reg_known_zero(struct bpf_verifier_env *env, } static void __mark_dynptr_reg(struct bpf_reg_state *reg, enum bpf_dynptr_type type, - bool first_slot, int dynptr_id) + bool first_slot, int id, int parent_id) { /* reg->type has no meaning for STACK_DYNPTR, but when we set reg for * callback arguments, it does need to be CONST_PTR_TO_DYNPTR, so simply @@ -1888,7 +1865,8 @@ static void __mark_dynptr_reg(struct bpf_reg_state *reg, enum bpf_dynptr_type ty __mark_reg_known_zero(reg); reg->type = CONST_PTR_TO_DYNPTR; /* Give each dynptr a unique id to uniquely associate slices to it. */ - reg->id = dynptr_id; + reg->id = id; + reg->parent_id = parent_id; reg->dynptr.type = type; reg->dynptr.first_slot = first_slot; } @@ -2168,17 +2146,12 @@ static int reg_bounds_sanity_check(struct bpf_verifier_env *env, /* Mark a register as having a completely unknown (scalar) value. */ void bpf_mark_reg_unknown_imprecise(struct bpf_reg_state *reg) { - /* - * Clear type, off, and union(map_ptr, range) and - * padding between 'type' and union - */ - memset(reg, 0, offsetof(struct bpf_reg_state, var_off)); + s32 subreg_def = reg->subreg_def; + + memset(reg, 0, sizeof(*reg)); reg->type = SCALAR_VALUE; - reg->id = 0; - reg->ref_obj_id = 0; reg->var_off = tnum_unknown; - reg->frameno = 0; - reg->precise = false; + reg->subreg_def = subreg_def; __mark_reg_unbounded(reg); } @@ -3006,50 +2979,13 @@ static int sort_subprogs_topo(struct bpf_verifier_env *env) return ret; } -static int mark_stack_slot_obj_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg, - int spi, int nr_slots) +static void mark_stack_slots_scratched(struct bpf_verifier_env *env, + int spi, int nr_slots) { int i; for (i = 0; i < nr_slots; i++) 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 - * check_kfunc_call. - */ - if (reg->type == CONST_PTR_TO_DYNPTR) - return 0; - spi = dynptr_get_spi(env, reg); - if (spi < 0) - return spi; - /* Caller ensures dynptr is valid and initialized, which means spi is in - * bounds and spi is the first dynptr slot. Simply mark stack slot as - * read. - */ - 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) -{ - return mark_stack_slot_obj_read(env, reg, spi, nr_slots); -} - -static int mark_irq_flag_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg) -{ - int spi; - - 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 @@ -4374,7 +4310,7 @@ static int map_kptr_match_type(struct bpf_verifier_env *env, * referenced PTR_TO_BTF_ID, and that its fixed offset is 0. For the * normal store of unreferenced kptr, we must ensure var_off is zero. * Since ref_ptr cannot be accessed directly by BPF insns, check for - * reg->ref_obj_id is not needed here. + * reg->id is not needed here. */ if (__check_ptr_off_reg(env, reg, argno_from_reg(regno), true)) return -EACCES; @@ -4747,8 +4683,8 @@ static int __check_ctx_access(struct bpf_verifier_env *env, int insn_idx, int of * type of narrower access. */ if (base_type(info->reg_type) == PTR_TO_BTF_ID) { - if (info->ref_obj_id && - !find_reference_state(env->cur_state, info->ref_obj_id)) { + if (info->ref_id && + !find_reference_state(env->cur_state, info->ref_id)) { verbose(env, "invalid bpf_context access off=%d. Reference may already be released\n", off); return -EACCES; @@ -4917,10 +4853,10 @@ static u32 *reg2btf_ids[__BPF_REG_TYPE_MAX] = { [CONST_PTR_TO_MAP] = btf_bpf_map_id, }; -static bool is_trusted_reg(const struct bpf_reg_state *reg) +static bool is_trusted_reg(struct bpf_verifier_env *env, const struct bpf_reg_state *reg) { /* A referenced register is always trusted. */ - if (reg->ref_obj_id) + if (reg_is_referenced(env, reg)) return true; /* Types listed in the reg2btf_ids are always trusted */ @@ -5834,7 +5770,7 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, ret = env->ops->btf_struct_access(&env->log, reg, off, size); } else { /* Writes are permitted with default btf_struct_access for - * program allocated objects (which always have ref_obj_id > 0), + * program allocated objects (which always have id > 0), * but not for untrusted PTR_TO_BTF_ID | MEM_ALLOC. */ if (atype != BPF_READ && !type_is_ptr_alloc_obj(reg->type)) { @@ -5843,8 +5779,8 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, } if (type_is_alloc(reg->type) && !type_is_non_owning_ref(reg->type) && - !(reg->type & MEM_RCU) && !reg->ref_obj_id) { - verifier_bug(env, "ref_obj_id for allocated object must be non-zero"); + !(reg->type & MEM_RCU) && !reg_is_referenced(env, reg)) { + verifier_bug(env, "allocated object must have a referenced id"); return -EFAULT; } @@ -5863,7 +5799,7 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, */ flag = PTR_UNTRUSTED; - } else if (is_trusted_reg(reg) || is_rcu_reg(reg)) { + } else if (is_trusted_reg(env, reg) || is_rcu_reg(reg)) { /* By default any pointer obtained from walking a trusted pointer is no * longer trusted, unless the field being accessed has explicitly been * marked as inheriting its parent's state of trust (either full or RCU). @@ -6252,8 +6188,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, struct b } else { mark_reg_known_zero(env, regs, value_regno); - if (type_may_be_null(info.reg_type)) - regs[value_regno].id = ++env->id_gen; /* A load of ctx field could have different * actual load size with the one encoded in the * insn. When the dst is PTR, it is for sure not @@ -6263,8 +6197,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, struct b if (base_type(info.reg_type) == PTR_TO_BTF_ID) { regs[value_regno].btf = info.btf; regs[value_regno].btf_id = info.btf_id; - regs[value_regno].ref_obj_id = info.ref_obj_id; + regs[value_regno].id = info.ref_id; } + if (type_may_be_null(info.reg_type) && !regs[value_regno].id) + regs[value_regno].id = ++env->id_gen; } regs[value_regno].type = info.reg_type; } @@ -7244,7 +7180,16 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno, return 0; } -/* There are two register types representing a bpf_dynptr, one is PTR_TO_STACK +/* + * Validate dynptr arguments for helper, kfunc and subprog. + * + * @dynptr is both input and output. It is populated when the argument is + * tagged with MEM_UNINIT (i.e., the dynptr argument that will be constructed) + * and consumed when the argument is expecting to be an initialized dynptr. + * @parent_id is used to track the referenced parent object (e.g., file or skb in + * qdisc program) when constructing a dynptr. + * + * There are two register types representing a bpf_dynptr, one is PTR_TO_STACK * which points to a stack slot, and the other is CONST_PTR_TO_DYNPTR. * * In both cases we deal with the first 8 bytes, but need to mark the next 8 @@ -7258,10 +7203,11 @@ static int process_kptr_func(struct bpf_verifier_env *env, int regno, * use case. The second level is tracked using the upper bit of bpf_dynptr->size * and checked dynamically during runtime. */ -static int process_dynptr_func(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno, int insn_idx, - enum bpf_arg_type arg_type, int clone_ref_obj_id) +static int process_dynptr_func(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + argno_t argno, int insn_idx, enum bpf_arg_type arg_type, + struct ref_obj_desc *ref_obj, struct bpf_dynptr_desc *dynptr) { - int err; + int spi, err = 0; if (reg->type != PTR_TO_STACK && reg->type != CONST_PTR_TO_DYNPTR) { verbose(env, @@ -7300,7 +7246,7 @@ static int process_dynptr_func(struct bpf_verifier_env *env, struct bpf_reg_stat return err; } - err = mark_stack_slots_dynptr(env, reg, arg_type, insn_idx, clone_ref_obj_id); + err = mark_stack_slots_dynptr(env, reg, arg_type, insn_idx, ref_obj, dynptr); } else /* OBJ_RELEASE and None case from above */ { /* For the reg->type == PTR_TO_STACK case, bpf_dynptr is never const */ if (reg->type == CONST_PTR_TO_DYNPTR && (arg_type & OBJ_RELEASE)) { @@ -7323,18 +7269,31 @@ static int process_dynptr_func(struct bpf_verifier_env *env, struct bpf_reg_stat return -EINVAL; } - err = mark_dynptr_read(env, reg); + if (reg->type != CONST_PTR_TO_DYNPTR) { + struct bpf_func_state *state = bpf_func(env, reg); + + spi = dynptr_get_spi(env, reg); + if (spi < 0) + return spi; + + /* + * For CONST_PTR_TO_DYNPTR, reg is already scratched by check_reg_arg + * in check_helper_call and mark_btf_func_reg_size in check_kfunc_call. + */ + mark_stack_slots_scratched(env, spi, BPF_DYNPTR_NR_SLOTS); + + reg = &state->stack[spi].spilled_ptr; + } + + if (dynptr) { + dynptr->type = reg->dynptr.type; + dynptr->id = reg->id; + dynptr->parent_id = reg->parent_id; + } } return err; } -static u32 iter_ref_obj_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg, int spi) -{ - struct bpf_func_state *state = bpf_func(env, reg); - - return state->stack[spi].spilled_ptr.ref_obj_id; -} - static bool is_iter_kfunc(struct bpf_kfunc_call_arg_meta *meta) { return meta->kfunc_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY); @@ -7367,6 +7326,7 @@ static bool is_kfunc_arg_iter(struct bpf_kfunc_call_arg_meta *meta, int arg_idx, static int process_iter_arg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno, int insn_idx, struct bpf_kfunc_call_arg_meta *meta) { + struct bpf_func_state *state = bpf_func(env, reg); const struct btf_type *t; u32 arg_idx = arg_idx_from_argno(argno); int spi, err, i, nr_slots, btf_id; @@ -7433,14 +7393,12 @@ static int process_iter_arg(struct bpf_verifier_env *env, struct bpf_reg_state * if (spi < 0) return spi; - err = mark_iter_read(env, reg, spi, nr_slots); - if (err) - return err; + mark_stack_slots_scratched(env, spi, nr_slots); /* remember meta->iter info for process_iter_next_call() */ meta->iter.spi = spi; meta->iter.frameno = reg->frameno; - meta->ref_obj_id = iter_ref_obj_id(env, reg, spi); + update_ref_obj(&meta->ref_obj, &state->stack[spi].spilled_ptr); if (is_iter_destroy_kfunc(meta)) { err = unmark_stack_slots_iter(env, reg, nr_slots); @@ -8023,7 +7981,7 @@ static int check_func_arg_reg_off(struct bpf_verifier_env *env, /* When referenced register is passed to release function, its fixed * offset must be 0. * - * We will check arg_type_is_release reg has ref_obj_id when storing + * We will check arg_type_is_release reg has id when storing * meta->release_regno. */ if (arg_type_is_release(arg_type)) { @@ -8094,72 +8052,6 @@ static int check_func_arg_reg_off(struct bpf_verifier_env *env, } } -static struct bpf_reg_state *get_dynptr_arg_reg(struct bpf_verifier_env *env, - const struct bpf_func_proto *fn, - struct bpf_reg_state *regs) -{ - struct bpf_reg_state *state = NULL; - int i; - - for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) - if (arg_type_is_dynptr(fn->arg_type[i])) { - if (state) { - verbose(env, "verifier internal error: multiple dynptr args\n"); - return NULL; - } - state = ®s[BPF_REG_1 + i]; - } - - if (!state) - verbose(env, "verifier internal error: no dynptr arg found\n"); - - return state; -} - -static int dynptr_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg) -{ - struct bpf_func_state *state = bpf_func(env, reg); - int spi; - - if (reg->type == CONST_PTR_TO_DYNPTR) - return reg->id; - spi = dynptr_get_spi(env, reg); - if (spi < 0) - return spi; - return state->stack[spi].spilled_ptr.id; -} - -static int dynptr_ref_obj_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg) -{ - struct bpf_func_state *state = bpf_func(env, reg); - int spi; - - if (reg->type == CONST_PTR_TO_DYNPTR) - return reg->ref_obj_id; - spi = dynptr_get_spi(env, reg); - if (spi < 0) - return spi; - return state->stack[spi].spilled_ptr.ref_obj_id; -} - -static enum bpf_dynptr_type dynptr_get_type(struct bpf_verifier_env *env, - struct bpf_reg_state *reg) -{ - struct bpf_func_state *state = bpf_func(env, reg); - int spi; - - if (reg->type == CONST_PTR_TO_DYNPTR) - return reg->dynptr.type; - - spi = bpf_get_spi(reg->var_off.value); - if (spi < 0) { - verbose(env, "verifier internal error: invalid spi when querying dynptr type\n"); - return BPF_DYNPTR_TYPE_INVALID; - } - - return state->stack[spi].spilled_ptr.dynptr.type; -} - static int check_arg_const_str(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno) { @@ -8285,6 +8177,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, u32 regno = BPF_REG_1 + arg; struct bpf_reg_state *reg = reg_state(env, regno); enum bpf_arg_type arg_type = fn->arg_type[arg]; + argno_t argno = argno_from_arg(arg + 1); enum bpf_reg_type type = reg->type; u32 *arg_btf_id = NULL; u32 key_size; @@ -8338,47 +8231,15 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, return err; skip_type_check: - if (arg_type_is_release(arg_type)) { - if (arg_type_is_dynptr(arg_type)) { - struct bpf_func_state *state = bpf_func(env, reg); - int spi; - - /* Only dynptr created on stack can be released, thus - * the get_spi and stack state checks for spilled_ptr - * should only be done before process_dynptr_func for - * PTR_TO_STACK. - */ - if (reg->type == PTR_TO_STACK) { - spi = dynptr_get_spi(env, reg); - if (spi < 0 || !state->stack[spi].spilled_ptr.ref_obj_id) { - verbose(env, "arg %d is an unacquired reference\n", regno); - return -EINVAL; - } - } else { - verbose(env, "cannot release unowned const bpf_dynptr\n"); - return -EINVAL; - } - } else if (!reg->ref_obj_id && !bpf_register_is_null(reg)) { - verbose(env, "R%d must be referenced when passed to release function\n", - regno); - return -EINVAL; - } - if (meta->release_regno) { - verifier_bug(env, "more than one release argument"); - return -EFAULT; - } - meta->release_regno = regno; + if (arg_type_is_release(arg_type) && !arg_type_is_dynptr(arg_type) && + !reg_is_referenced(env, reg) && !bpf_register_is_null(reg)) { + verbose(env, "release helper %s expects referenced PTR_TO_BTF_ID passed to %s\n", + func_id_name(meta->func_id), reg_arg_name(env, argno)); + return -EINVAL; } - if (reg->ref_obj_id && base_type(arg_type) != ARG_KPTR_XCHG_DEST) { - if (meta->ref_obj_id) { - verbose(env, "more than one arg with ref_obj_id R%d %u %u", - regno, reg->ref_obj_id, - meta->ref_obj_id); - return -EACCES; - } - meta->ref_obj_id = reg->ref_obj_id; - } + if (reg_is_referenced(env, reg)) + update_ref_obj(&meta->ref_obj, reg); switch (base_type(arg_type)) { case ARG_CONST_MAP_PTR: @@ -8517,7 +8378,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, true, meta); break; case ARG_PTR_TO_DYNPTR: - err = process_dynptr_func(env, reg, argno_from_reg(regno), insn_idx, arg_type, 0); + err = process_dynptr_func(env, reg, argno_from_reg(regno), insn_idx, arg_type, &meta->ref_obj, + &meta->dynptr); if (err) return err; break; @@ -8936,11 +8798,29 @@ static bool check_mem_arg_rw_flag_ok(const struct bpf_func_proto *fn) return true; } -static int check_func_proto(const struct bpf_func_proto *fn) +static bool check_proto_release_reg(const struct bpf_func_proto *fn, struct bpf_call_arg_meta *meta) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) { + enum bpf_arg_type arg_type = fn->arg_type[i]; + + if (arg_type_is_release(arg_type)) { + if (meta->release_regno) + return false; + meta->release_regno = i + 1; + } + } + + return true; +} + +static int check_func_proto(const struct bpf_func_proto *fn, struct bpf_call_arg_meta *meta) { return check_raw_mode_ok(fn) && check_arg_pair_ok(fn) && check_mem_arg_rw_flag_ok(fn) && + check_proto_release_reg(fn, meta) && check_btf_id_ok(fn) ? 0 : -EINVAL; } @@ -8987,14 +8867,14 @@ 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) +static int release_reference_nomark(struct bpf_verifier_state *state, int 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) { + if (state->refs[i].id == id) { release_reference_state(state, i); return 0; } @@ -9002,26 +8882,83 @@ static int release_reference_nomark(struct bpf_verifier_state *state, int ref_ob 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 idstack_push(struct bpf_idmap *idmap, u32 id) { + int i; + + if (!id) + return 0; + + for (i = 0; i < idmap->cnt; i++) + if (idmap->map[i].old == id) + return 0; + + if (WARN_ON_ONCE(idmap->cnt >= BPF_ID_MAP_SIZE)) + return -EFAULT; + + idmap->map[idmap->cnt++].old = id; + return 0; +} + +static int idstack_pop(struct bpf_idmap *idmap) +{ + if (!idmap->cnt) + return 0; + + return idmap->map[--idmap->cnt].old; +} + +/* Release id and objects derived from it iteratively in a DFS manner */ +static int release_reference(struct bpf_verifier_env *env, int id) +{ + u32 mask = (1 << STACK_SPILL) | (1 << STACK_DYNPTR); struct bpf_verifier_state *vstate = env->cur_state; + struct bpf_idmap *idstack = &env->idmap_scratch; + struct bpf_stack_state *stack; struct bpf_func_state *state; struct bpf_reg_state *reg; - int err; + int i, err; - err = release_reference_nomark(vstate, ref_obj_id); + idstack->cnt = 0; + err = idstack_push(idstack, id); if (err) return err; - bpf_for_each_reg_in_vstate(vstate, state, reg, ({ - if (reg->ref_obj_id == ref_obj_id) - mark_reg_invalid(env, reg); - })); + if (find_reference_state(vstate, id)) + WARN_ON_ONCE(release_reference_nomark(vstate, id)); + + while ((id = idstack_pop(idstack))) { + /* + * Child references are inaccessible after parent is released, + * any child references that exist at this point are a leak. + */ + for (i = 0; i < vstate->acquired_refs; i++) { + if (vstate->refs[i].type != REF_TYPE_PTR) + continue; + if (vstate->refs[i].parent_id != id) + continue; + verbose(env, "Leaking reference id=%d alloc_insn=%d. Release it first.\n", + vstate->refs[i].id, vstate->refs[i].insn_idx); + return -EINVAL; + } + + bpf_for_each_reg_in_vstate_mask(vstate, state, reg, stack, mask, ({ + if (reg->id != id && reg->parent_id != id) + continue; + + /* Free objects derived from the current object */ + if (reg->parent_id == id) { + err = idstack_push(idstack, reg->id); + if (err) + return err; + } + + if (!stack || stack->slot_type[BPF_REG_SIZE - 1] == STACK_SPILL) + mark_reg_invalid(env, reg); + else if (stack->slot_type[BPF_REG_SIZE - 1] == STACK_DYNPTR) + invalidate_dynptr(env, stack); + })); + } return 0; } @@ -9037,6 +8974,42 @@ static void invalidate_non_owning_refs(struct bpf_verifier_env *env) })); } +static void invalidate_rcu_protected_refs(struct bpf_verifier_env *env) +{ + struct bpf_stack_state *stack; + struct bpf_func_state *state; + struct bpf_reg_state *reg; + u32 clear_mask = (1 << STACK_SPILL) | (1 << STACK_ITER); + + bpf_for_each_reg_in_vstate_mask(env->cur_state, state, reg, stack, clear_mask, ({ + if (reg->type & MEM_RCU) { + reg->type &= ~(MEM_RCU | PTR_MAYBE_NULL); + reg->type |= PTR_UNTRUSTED; + } + })); +} + +static int ref_convert_alloc_rcu_protected(struct bpf_verifier_env *env, u32 id) +{ + struct bpf_func_state *state; + struct bpf_reg_state *reg; + int err; + + err = release_reference_nomark(env->cur_state, id); + + bpf_for_each_reg_in_vstate(env->cur_state, state, reg, ({ + if (reg->id != id) + continue; + if ((reg->type & MEM_ALLOC) && (reg->type & MEM_PERCPU)) { + reg->id = 0; + reg->type &= ~MEM_ALLOC; + reg->type |= MEM_RCU; + } + })); + + return err; +} + static void clear_caller_saved_regs(struct bpf_verifier_env *env, struct bpf_reg_state *regs) { @@ -9122,6 +9095,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, struct bpf_subprog_info *sub = subprog_info(env, subprog); struct bpf_func_state *caller = cur_func(env); struct bpf_verifier_log *log = &env->log; + struct ref_obj_desc ref_obj = {}; u32 i; int ret, err; @@ -9199,7 +9173,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, if (ret) return ret; - ret = process_dynptr_func(env, reg, argno, -1, arg->arg_type, 0); + ret = process_dynptr_func(env, reg, argno, -1, arg->arg_type, &ref_obj, NULL); if (ret) return ret; } else if (base_type(arg->arg_type) == ARG_PTR_TO_BTF_ID) { @@ -9922,7 +9896,7 @@ static int check_reference_leak(struct bpf_verifier_env *env, bool exception_exi * kernel. Type checks are performed later in check_return_code. */ if (type == BPF_PROG_TYPE_STRUCT_OPS && !exception_exit && - reg->ref_obj_id == state->refs[i].id) + reg->id == state->refs[i].id) continue; verbose(env, "Unreleased reference id=%d alloc_insn=%d\n", state->refs[i].id, state->refs[i].insn_idx); @@ -10108,6 +10082,24 @@ static const char *non_sleepable_context_description(struct bpf_verifier_env *en return "non-sleepable prog"; } +static int release_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + bool convert_rcu, bool release_dynptr) +{ + int err = -EINVAL; + + if (bpf_register_is_null(reg)) + return 0; + + if (release_dynptr) + err = unmark_stack_slots_dynptr(env, reg); + else if (convert_rcu) + err = ref_convert_alloc_rcu_protected(env, reg->id); + else if (reg_is_referenced(env, reg)) + err = release_reference(env, reg->id); + + return err; +} + static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { @@ -10157,7 +10149,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn memset(&meta, 0, sizeof(meta)); meta.pkt_access = fn->pkt_access; - err = check_func_proto(fn); + err = check_func_proto(fn, &meta); if (err) { verifier_bug(env, "incorrect func proto %s#%d", func_id_name(func_id), func_id); return err; @@ -10202,42 +10194,13 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn } if (meta.release_regno) { - err = -EINVAL; - if (arg_type_is_dynptr(fn->arg_type[meta.release_regno - BPF_REG_1])) { - err = unmark_stack_slots_dynptr(env, ®s[meta.release_regno]); - } else if (func_id == BPF_FUNC_kptr_xchg && meta.ref_obj_id) { - u32 ref_obj_id = meta.ref_obj_id; - bool in_rcu = in_rcu_cs(env); - struct bpf_func_state *state; - struct bpf_reg_state *reg; + struct bpf_reg_state *reg = ®s[meta.release_regno]; + bool convert_rcu = (func_id == BPF_FUNC_kptr_xchg) && in_rcu_cs(env) && + (reg->type & MEM_ALLOC) && (reg->type & MEM_PERCPU); - 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) { - if (in_rcu && (reg->type & MEM_ALLOC) && (reg->type & MEM_PERCPU)) { - reg->ref_obj_id = 0; - reg->type &= ~MEM_ALLOC; - reg->type |= MEM_RCU; - } else { - mark_reg_invalid(env, reg); - } - } - })); - } - } else if (meta.ref_obj_id) { - err = release_reference(env, meta.ref_obj_id); - } else if (bpf_register_is_null(®s[meta.release_regno])) { - /* meta.ref_obj_id can only be 0 if register that is meant to be - * released is NULL, which must be > R0. - */ - err = 0; - } - if (err) { - verbose(env, "func %s#%d reference has not been acquired before\n", - func_id_name(func_id), func_id); + err = release_reg(env, reg, convert_rcu, !!meta.dynptr.id); + if (err) return err; - } } switch (func_id) { @@ -10307,52 +10270,10 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn } } break; - case BPF_FUNC_dynptr_data: - { - struct bpf_reg_state *reg; - int id, ref_obj_id; - - reg = get_dynptr_arg_reg(env, fn, regs); - if (!reg) - return -EFAULT; - - - if (meta.dynptr_id) { - verifier_bug(env, "meta.dynptr_id already set"); - return -EFAULT; - } - if (meta.ref_obj_id) { - verifier_bug(env, "meta.ref_obj_id already set"); - return -EFAULT; - } - - id = dynptr_id(env, reg); - if (id < 0) { - verifier_bug(env, "failed to obtain dynptr id"); - return id; - } - - ref_obj_id = dynptr_ref_obj_id(env, reg); - if (ref_obj_id < 0) { - verifier_bug(env, "failed to obtain dynptr ref_obj_id"); - return ref_obj_id; - } - - meta.dynptr_id = id; - meta.ref_obj_id = ref_obj_id; - - break; - } case BPF_FUNC_dynptr_write: { - enum bpf_dynptr_type dynptr_type; - struct bpf_reg_state *reg; + enum bpf_dynptr_type dynptr_type = meta.dynptr.type; - reg = get_dynptr_arg_reg(env, fn, regs); - if (!reg) - return -EFAULT; - - dynptr_type = dynptr_get_type(env, reg); if (dynptr_type == BPF_DYNPTR_TYPE_INVALID) return -EFAULT; @@ -10538,29 +10459,45 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn if (type_may_be_null(regs[BPF_REG_0].type)) regs[BPF_REG_0].id = ++env->id_gen; - if (helper_multiple_ref_obj_use(func_id, meta.map.ptr)) { - verifier_bug(env, "func %s#%d sets ref_obj_id more than once", - func_id_name(func_id), func_id); - return -EFAULT; - } + if (is_ptr_cast_function(func_id) && + find_reference_state(env->cur_state, meta.ref_obj.id)) { + struct bpf_verifier_state *branch; + struct bpf_reg_state *r0; - if (is_dynptr_ref_function(func_id)) - regs[BPF_REG_0].dynptr_id = meta.dynptr_id; + err = validate_ref_obj(env, &meta.ref_obj); + if (err) + return err; - if (is_ptr_cast_function(func_id) || is_dynptr_ref_function(func_id)) { - /* For release_reference() */ - regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id; + /* + * In order for a release of any of the original or cast pointers + * to invalidate all other pointers, reuse the same reference id for + * the cast result. + * This reference id can't be used for nullness propagation, + * as cast might return NULL for a non-NULL input. + * Hence, explore the NULL case as a separate branch. + */ + branch = push_stack(env, env->insn_idx + 1, env->insn_idx, false); + if (IS_ERR(branch)) + return PTR_ERR(branch); + + r0 = &branch->frame[branch->curframe]->regs[BPF_REG_0]; + __mark_reg_known_zero(r0); + r0->type = SCALAR_VALUE; + + regs[BPF_REG_0].type &= ~PTR_MAYBE_NULL; + regs[BPF_REG_0].id = meta.ref_obj.id; } else if (is_acquire_function(func_id, meta.map.ptr)) { - int id = acquire_reference(env, insn_idx); + int id = acquire_reference(env, insn_idx, 0); 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; } + if (func_id == BPF_FUNC_dynptr_data) + regs[BPF_REG_0].parent_id = meta.dynptr.id; + err = do_refine_retval_range(env, regs, fn->ret_type, func_id, &meta); if (err) return err; @@ -10656,7 +10593,6 @@ static bool is_kfunc_release(struct bpf_kfunc_call_arg_meta *meta) return meta->kfunc_flags & KF_RELEASE; } - static bool is_kfunc_destructive(struct bpf_kfunc_call_arg_meta *meta) { return meta->kfunc_flags & KF_DESTRUCTIVE; @@ -11371,7 +11307,7 @@ static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env, * btf_struct_ids_match() to walk the struct at the 0th offset, and * resolve types. */ - if ((is_kfunc_release(meta) && reg->ref_obj_id) || + if ((is_kfunc_release(meta) && reg_is_referenced(env, reg)) || btf_type_ids_nocast_alias(&env->log, reg_btf, reg_ref_id, meta->btf, ref_id)) strict_type_match = true; @@ -11399,7 +11335,7 @@ static int process_kf_arg_ptr_to_btf_id(struct bpf_verifier_env *env, static int process_irq_flag(struct bpf_verifier_env *env, struct bpf_reg_state *reg, argno_t argno, struct bpf_kfunc_call_arg_meta *meta) { - int err, kfunc_class = IRQ_NATIVE_KFUNC; + int err, spi, kfunc_class = IRQ_NATIVE_KFUNC; bool irq_save; if (meta->func_id == special_kfunc_list[KF_bpf_local_irq_save] || @@ -11440,9 +11376,11 @@ static int process_irq_flag(struct bpf_verifier_env *env, struct bpf_reg_state * return err; } - err = mark_irq_flag_read(env, reg); - if (err) - return err; + spi = irq_flag_get_spi(env, reg); + if (spi < 0) + return spi; + + mark_stack_slots_scratched(env, spi, 1); err = unmark_stack_slot_irq_flag(env, reg, kfunc_class); if (err) @@ -11473,36 +11411,21 @@ static int ref_set_non_owning(struct bpf_verifier_env *env, struct bpf_reg_state return 0; } -static int ref_convert_owning_non_owning(struct bpf_verifier_env *env, u32 ref_obj_id) +static void ref_convert_owning_non_owning(struct bpf_verifier_env *env, u32 id) { - struct bpf_verifier_state *state = env->cur_state; struct bpf_func_state *unused; struct bpf_reg_state *reg; - int i; - if (!ref_obj_id) { - verifier_bug(env, "ref_obj_id is zero for owning -> non-owning conversion"); - return -EFAULT; - } + WARN_ON_ONCE(release_reference_nomark(env->cur_state, id)); - for (i = 0; i < state->acquired_refs; i++) { - if (state->refs[i].id != ref_obj_id) - continue; + bpf_for_each_reg_in_vstate(env->cur_state, unused, reg, ({ + if (reg->id == id) { + reg->id = 0; + ref_set_non_owning(env, reg); + } + })); - /* Clear ref_obj_id here so release_reference doesn't clobber - * the whole reg - */ - bpf_for_each_reg_in_vstate(env->cur_state, unused, reg, ({ - if (reg->ref_obj_id == ref_obj_id) { - reg->ref_obj_id = 0; - ref_set_non_owning(env, reg); - } - })); - return 0; - } - - verifier_bug(env, "ref state missing for ref_obj_id"); - return -EFAULT; + return; } /* Implementation details: @@ -12034,24 +11957,16 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return -EACCES; } - if (reg->ref_obj_id) { - if (is_kfunc_release(meta) && meta->ref_obj_id) { - verifier_bug(env, "more than one arg with ref_obj_id %s %u %u", - reg_arg_name(env, argno), reg->ref_obj_id, - meta->ref_obj_id); - return -EFAULT; - } - meta->ref_obj_id = reg->ref_obj_id; - if (is_kfunc_release(meta)) { - if (regno < 0) { - verbose(env, "%s release arg cannot be a stack argument\n", - reg_arg_name(env, argno)); - return -EINVAL; - } - meta->release_regno = regno; - } + if (regno == meta->release_regno && !is_kfunc_arg_dynptr(meta->btf, &args[i]) && + !reg_is_referenced(env, reg) && !bpf_register_is_null(reg)) { + verbose(env, "release kfunc %s expects referenced PTR_TO_BTF_ID passed to %s\n", + func_name, reg_arg_name(env, argno)); + return -EINVAL; } + if (reg_is_referenced(env, reg)) + update_ref_obj(&meta->ref_obj, reg); + ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id); ref_tname = btf_name_by_offset(btf, ref_t->name_off); @@ -12102,7 +12017,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ fallthrough; case KF_ARG_PTR_TO_ALLOC_BTF_ID: case KF_ARG_PTR_TO_BTF_ID: - if (!is_trusted_reg(reg)) { + if (!is_trusted_reg(env, reg)) { if (!is_kfunc_rcu(meta)) { verbose(env, "%s must be referenced or trusted\n", reg_arg_name(env, argno)); @@ -12115,7 +12030,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ } } fallthrough; - case KF_ARG_PTR_TO_DYNPTR: case KF_ARG_PTR_TO_ITER: case KF_ARG_PTR_TO_LIST_HEAD: case KF_ARG_PTR_TO_LIST_NODE: @@ -12132,6 +12046,9 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_IRQ_FLAG: case KF_ARG_PTR_TO_RES_SPIN_LOCK: break; + case KF_ARG_PTR_TO_DYNPTR: + arg_type = ARG_PTR_TO_DYNPTR; + break; case KF_ARG_PTR_TO_CTX: arg_type = ARG_PTR_TO_CTX; break; @@ -12140,7 +12057,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return -EFAULT; } - if (is_kfunc_release(meta) && reg->ref_obj_id) + if (regno == meta->release_regno) arg_type |= OBJ_RELEASE; ret = check_func_arg_reg_off(env, reg, argno, arg_type); if (ret < 0) @@ -12179,7 +12096,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ reg_arg_name(env, argno)); return -EINVAL; } - if (!reg->ref_obj_id) { + if (!reg_is_referenced(env, reg)) { verbose(env, "allocated object must be referenced\n"); return -EINVAL; } @@ -12191,7 +12108,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_DYNPTR: { enum bpf_arg_type dynptr_arg_type = ARG_PTR_TO_DYNPTR; - int clone_ref_obj_id = 0; if (is_kfunc_arg_uninit(btf, &args[i])) dynptr_arg_type |= MEM_UNINIT; @@ -12206,15 +12122,9 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ dynptr_arg_type |= DYNPTR_TYPE_FILE; } else if (meta->func_id == special_kfunc_list[KF_bpf_dynptr_file_discard]) { dynptr_arg_type |= DYNPTR_TYPE_FILE | OBJ_RELEASE; - if (regno < 0) { - verbose(env, "%s release arg cannot be a stack argument\n", - reg_arg_name(env, argno)); - return -EINVAL; - } - meta->release_regno = regno; } else if (meta->func_id == special_kfunc_list[KF_bpf_dynptr_clone] && (dynptr_arg_type & MEM_UNINIT)) { - enum bpf_dynptr_type parent_type = meta->initialized_dynptr.type; + enum bpf_dynptr_type parent_type = meta->dynptr.type; if (parent_type == BPF_DYNPTR_TYPE_INVALID) { verifier_bug(env, "no dynptr type for parent of clone"); @@ -12222,30 +12132,12 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ } dynptr_arg_type |= (unsigned int)get_dynptr_type_flag(parent_type); - clone_ref_obj_id = meta->initialized_dynptr.ref_obj_id; - if (dynptr_type_refcounted(parent_type) && !clone_ref_obj_id) { - verifier_bug(env, "missing ref obj id for parent of clone"); - return -EFAULT; - } } - ret = process_dynptr_func(env, reg, argno, insn_idx, - dynptr_arg_type, clone_ref_obj_id); + ret = process_dynptr_func(env, reg, argno, insn_idx, dynptr_arg_type, + &meta->ref_obj, &meta->dynptr); if (ret < 0) return ret; - - if (!(dynptr_arg_type & MEM_UNINIT)) { - int id = dynptr_id(env, reg); - - if (id < 0) { - verifier_bug(env, "failed to obtain dynptr id"); - return id; - } - meta->initialized_dynptr.id = id; - meta->initialized_dynptr.type = dynptr_get_type(env, reg); - meta->initialized_dynptr.ref_obj_id = dynptr_ref_obj_id(env, reg); - } - break; } case KF_ARG_PTR_TO_ITER: @@ -12266,7 +12158,8 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ reg_arg_name(env, argno)); return -EINVAL; } - if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && !reg->ref_obj_id) { + if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && + !reg_is_referenced(env, reg)) { verbose(env, "allocated object must be referenced\n"); return -EINVAL; } @@ -12281,7 +12174,8 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ reg_arg_name(env, argno)); return -EINVAL; } - if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && !reg->ref_obj_id) { + if (reg->type == (PTR_TO_BTF_ID | MEM_ALLOC) && + !reg_is_referenced(env, reg)) { verbose(env, "allocated object must be referenced\n"); return -EINVAL; } @@ -12291,7 +12185,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ break; case KF_ARG_PTR_TO_LIST_NODE: if (is_kfunc_arg_nonown_allowed(btf, &args[i]) && - type_is_non_owning_ref(reg->type) && !reg->ref_obj_id) { + type_is_non_owning_ref(reg->type) && !reg_is_referenced(env, reg)) { /* Allow bpf_list_front/back return value for * __nonown_allowed list-node arguments. */ @@ -12302,7 +12196,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ reg_arg_name(env, argno)); return -EINVAL; } - if (!reg->ref_obj_id) { + if (!reg_is_referenced(env, reg)) { verbose(env, "allocated object must be referenced\n"); return -EINVAL; } @@ -12318,12 +12212,13 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ reg_arg_name(env, argno)); return -EINVAL; } - if (!reg->ref_obj_id) { + if (!reg_is_referenced(env, reg)) { verbose(env, "allocated object must be referenced\n"); return -EINVAL; } } else { - if (!type_is_non_owning_ref(reg->type) && !reg->ref_obj_id) { + if (!type_is_non_owning_ref(reg->type) && + !reg_is_referenced(env, reg)) { verbose(env, "%s can only take non-owning or refcounted bpf_rb_node pointer\n", func_name); return -EINVAL; } @@ -12515,12 +12410,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ } } - if (is_kfunc_release(meta) && !meta->release_regno) { - verbose(env, "release kernel function %s expects refcounted PTR_TO_BTF_ID\n", - func_name); - return -EINVAL; - } - return 0; } @@ -12547,6 +12436,10 @@ int bpf_fetch_kfunc_arg_meta(struct bpf_verifier_env *env, meta->kfunc_flags = *kfunc.flags; + /* Only support release referenced argument passed by register */ + if (is_kfunc_release(meta)) + meta->release_regno = BPF_REG_1; + return 0; } @@ -12876,7 +12769,7 @@ static int check_special_kfunc(struct bpf_verifier_env *env, struct bpf_kfunc_ca } } else if (meta->func_id == special_kfunc_list[KF_bpf_dynptr_slice] || meta->func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) { - enum bpf_type_flag type_flag = get_dynptr_type_flag(meta->initialized_dynptr.type); + enum bpf_type_flag type_flag = get_dynptr_type_flag(meta->dynptr.type); mark_reg_known_zero(env, regs, BPF_REG_0); @@ -12900,16 +12793,11 @@ static int check_special_kfunc(struct bpf_verifier_env *env, struct bpf_kfunc_ca } } - if (!meta->initialized_dynptr.id) { + if (!meta->dynptr.id) { verifier_bug(env, "no dynptr id"); return -EFAULT; } - regs[BPF_REG_0].dynptr_id = meta->initialized_dynptr.id; - - /* we don't need to set BPF_REG_0's ref obj id - * because packet slices are not refcounted (see - * dynptr_type_refcounted) - */ + regs[BPF_REG_0].parent_id = meta->dynptr.id; } else { return 0; } @@ -12923,13 +12811,13 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { bool sleepable, rcu_lock, rcu_unlock, preempt_disable, preempt_enable; - u32 i, nargs, ptr_type_id, release_ref_obj_id; struct bpf_reg_state *regs = cur_regs(env); const char *func_name, *ptr_type_name; const struct btf_type *t, *ptr_type; struct bpf_kfunc_call_arg_meta meta; struct bpf_insn_aux_data *insn_aux; int err, insn_idx = *insn_idx_p; + u32 i, nargs, ptr_type_id, id; const struct btf_param *args; struct btf *desc_btf; @@ -13042,22 +12930,12 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, if (rcu_lock) { env->cur_state->active_rcu_locks++; } else if (rcu_unlock) { - struct bpf_func_state *state; - struct bpf_reg_state *reg; - u32 clear_mask = (1 << STACK_SPILL) | (1 << STACK_ITER); - if (env->cur_state->active_rcu_locks == 0) { verbose(env, "unmatched rcu read unlock (kernel function %s)\n", func_name); return -EINVAL; } - if (--env->cur_state->active_rcu_locks == 0) { - bpf_for_each_reg_in_vstate_mask(env->cur_state, state, reg, clear_mask, ({ - if (reg->type & MEM_RCU) { - reg->type &= ~(MEM_RCU | PTR_MAYBE_NULL); - reg->type |= PTR_UNTRUSTED; - } - })); - } + if (--env->cur_state->active_rcu_locks == 0) + invalidate_rcu_protected_refs(env); } else if (preempt_disable) { env->cur_state->active_preempt_locks++; } else if (preempt_enable) { @@ -13088,37 +12966,16 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, * PTR_TO_BTF_ID in bpf_kfunc_arg_meta, do the release now. */ if (meta.release_regno) { - struct bpf_reg_state *reg = ®s[meta.release_regno]; - - if (meta.initialized_dynptr.ref_obj_id) { - err = unmark_stack_slots_dynptr(env, reg); - } else { - err = release_reference(env, reg->ref_obj_id); - if (err) - verbose(env, "kfunc %s#%d reference has not been acquired before\n", - func_name, meta.func_id); - } + err = release_reg(env, ®s[meta.release_regno], false, !!meta.dynptr.id); if (err) return err; } if (is_bpf_list_push_kfunc(meta.func_id) || is_bpf_rbtree_add_kfunc(meta.func_id)) { - release_ref_obj_id = regs[BPF_REG_2].ref_obj_id; + id = regs[BPF_REG_2].id; insn_aux->insert_off = regs[BPF_REG_2].var_off.value; insn_aux->kptr_struct_meta = btf_find_struct_meta(meta.arg_btf, meta.arg_btf_id); - err = ref_convert_owning_non_owning(env, release_ref_obj_id); - if (err) { - verbose(env, "kfunc %s#%d conversion of owning ref to non-owning failed\n", - func_name, meta.func_id); - return err; - } - - err = release_reference(env, release_ref_obj_id); - if (err) { - verbose(env, "kfunc %s#%d reference has not been acquired before\n", - func_name, meta.func_id); - return err; - } + ref_convert_owning_non_owning(env, id); } if (meta.func_id == special_kfunc_list[KF_bpf_throw]) { @@ -13203,8 +13060,12 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, regs[BPF_REG_0].type |= MEM_RDONLY; /* Ensures we don't access the memory after a release_reference() */ - if (meta.ref_obj_id) - regs[BPF_REG_0].ref_obj_id = meta.ref_obj_id; + if (meta.ref_obj.id) { + err = validate_ref_obj(env, &meta.ref_obj); + if (err) + return err; + regs[BPF_REG_0].parent_id = meta.ref_obj.id; + } if (is_kfunc_rcu_protected(&meta)) regs[BPF_REG_0].type |= MEM_RCU; @@ -13250,13 +13111,10 @@ 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(env, insn_idx); - + id = acquire_reference(env, insn_idx, 0); if (id < 0) return id; - if (is_kfunc_ret_null(&meta)) - regs[BPF_REG_0].id = id; - regs[BPF_REG_0].ref_obj_id = id; + regs[BPF_REG_0].id = id; } else if (is_rbtree_node_type(ptr_type) || is_list_node_type(ptr_type)) { ref_set_non_owning(env, ®s[BPF_REG_0]); } @@ -15487,7 +15345,7 @@ static int is_branch_taken(struct bpf_verifier_env *env, struct bpf_reg_state *r if (!is_reg_const(reg2, is_jmp32)) return -1; - if (!reg_not_null(reg1)) + if (!reg_not_null(env, reg1)) return -1; /* If pointer is valid tests against zero will fail so we can @@ -15704,7 +15562,7 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, WARN_ON_ONCE(!tnum_equals_const(reg->var_off, 0))) return; if (is_null) { - /* We don't need id and ref_obj_id from this point + /* We don't need id from this point * onwards anymore, thus we should better reset it, * so that state pruning has chances to take effect. */ @@ -15716,15 +15574,10 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, mark_ptr_not_null_reg(reg); - if (!reg_may_point_to_spin_lock(reg)) { - /* For not-NULL ptr, reg->ref_obj_id will be reset - * in release_reference(). - * - * reg->id is still used by spin_lock ptr. Other - * than spin_lock ptr type, reg->id can be reset. - */ - reg->id = 0; - } + /* + * reg->id is preserved for object relationship tracking + * and spin_lock lock state tracking + */ } } @@ -15736,10 +15589,9 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno, { struct bpf_func_state *state = vstate->frame[vstate->curframe]; struct bpf_reg_state *regs = state->regs, *reg; - u32 ref_obj_id = regs[regno].ref_obj_id; u32 id = regs[regno].id; - if (ref_obj_id && ref_obj_id == id && is_null) + if (is_null && find_reference_state(vstate, id)) /* regs[regno] is in the " == NULL" branch. * No one could have freed the reference state before * doing the NULL check. @@ -16578,7 +16430,7 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char ret_type = btf_type_resolve_ptr(prog->aux->attach_btf, prog->aux->attach_func_proto->type, NULL); - if (ret_type && ret_type == reg_type && reg->ref_obj_id) + if (ret_type && ret_type == reg_type && reg_is_referenced(env, reg)) return __check_ptr_off_reg(env, reg, argno_from_reg(regno), false); } @@ -18447,7 +18299,7 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) mark_reg_unknown(env, regs, i); } else if (arg->arg_type == ARG_PTR_TO_DYNPTR) { /* assume unspecial LOCAL dynptr type */ - __mark_dynptr_reg(reg, BPF_DYNPTR_TYPE_LOCAL, true, ++env->id_gen); + __mark_dynptr_reg(reg, BPF_DYNPTR_TYPE_LOCAL, true, ++env->id_gen, 0); } else if (base_type(arg->arg_type) == ARG_PTR_TO_MEM) { reg->type = PTR_TO_MEM; reg->type |= arg->arg_type & @@ -18506,8 +18358,8 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog) /* Acquire references for struct_ops program arguments tagged with "__ref" */ if (!subprog && env->prog->type == BPF_PROG_TYPE_STRUCT_OPS) { for (i = 0; i < aux->ctx_arg_info_size; i++) - aux->ctx_arg_info[i].ref_obj_id = aux->ctx_arg_info[i].refcounted ? - acquire_reference(env, 0) : 0; + aux->ctx_arg_info[i].ref_id = aux->ctx_arg_info[i].refcounted ? + acquire_reference(env, 0, 0) : 0; } ret = do_check(env); diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c b/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c index 730357cd0c9a..77f1c0550c9b 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_qdisc.c @@ -8,6 +8,10 @@ #include "bpf_qdisc_fifo.skel.h" #include "bpf_qdisc_fq.skel.h" #include "bpf_qdisc_fail__incompl_ops.skel.h" +#include "bpf_qdisc_fail__invalid_dynptr.skel.h" +#include "bpf_qdisc_fail__invalid_dynptr_slice.skel.h" +#include "bpf_qdisc_fail__invalid_dynptr_cross_frame.skel.h" +#include "bpf_qdisc_dynptr_use_after_invalidate_clone.skel.h" #define LO_IFINDEX 1 @@ -223,6 +227,10 @@ void test_ns_bpf_qdisc(void) test_qdisc_attach_to_non_root(); if (test__start_subtest("incompl_ops")) test_incompl_ops(); + RUN_TESTS(bpf_qdisc_fail__invalid_dynptr); + RUN_TESTS(bpf_qdisc_fail__invalid_dynptr_cross_frame); + RUN_TESTS(bpf_qdisc_fail__invalid_dynptr_slice); + RUN_TESTS(bpf_qdisc_dynptr_use_after_invalidate_clone); } void serial_test_bpf_qdisc_default(void) diff --git a/tools/testing/selftests/bpf/prog_tests/cb_refs.c b/tools/testing/selftests/bpf/prog_tests/cb_refs.c index 6300b67a3a84..78566b817fd7 100644 --- a/tools/testing/selftests/bpf/prog_tests/cb_refs.c +++ b/tools/testing/selftests/bpf/prog_tests/cb_refs.c @@ -11,7 +11,7 @@ struct { const char *prog_name; const char *err_msg; } cb_refs_tests[] = { - { "underflow_prog", "must point to scalar, or struct with scalar" }, + { "underflow_prog", "release kfunc bpf_kfunc_call_test_release expects referenced PTR_TO_BTF_ID passed to R1" }, { "leak_prog", "Possibly NULL pointer passed to helper R2" }, { "nested_cb", "Unreleased reference id=4 alloc_insn=2" }, /* alloc_insn=2{4,5} */ { "non_cb_transfer_ref", "Unreleased reference id=4 alloc_insn=1" }, /* alloc_insn=1{1,2} */ diff --git a/tools/testing/selftests/bpf/prog_tests/spin_lock.c b/tools/testing/selftests/bpf/prog_tests/spin_lock.c index bbe476f4c47d..5c3579438427 100644 --- a/tools/testing/selftests/bpf/prog_tests/spin_lock.c +++ b/tools/testing/selftests/bpf/prog_tests/spin_lock.c @@ -13,8 +13,8 @@ static struct { const char *err_msg; } spin_lock_fail_tests[] = { { "lock_id_kptr_preserve", - "[0-9]\\+: (bf) r1 = r0 ; R0=ptr_foo(id=2,ref_obj_id=2)" - " R1=ptr_foo(id=2,ref_obj_id=2) refs=2\n" + "[0-9]\\+: (bf) r1 = r0 ; R0=ptr_foo(id=2)" + " R1=ptr_foo(id=2) refs=2\n" "[0-9]\\+: (85) call bpf_this_cpu_ptr#154\n" "R1 type=ptr_ expected=percpu_ptr_" }, { "lock_id_global_zero", diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_dynptr_use_after_invalidate_clone.c b/tools/testing/selftests/bpf/progs/bpf_qdisc_dynptr_use_after_invalidate_clone.c new file mode 100644 index 000000000000..ac626cfa2a98 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_dynptr_use_after_invalidate_clone.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf_experimental.h" +#include "bpf_qdisc_common.h" +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +int proto; + +SEC("struct_ops") +__success +int BPF_PROG(dynptr_use_after_invalidate_clone, struct sk_buff *skb, struct Qdisc *sch, + struct bpf_sk_buff_ptr *to_free) +{ + struct bpf_dynptr ptr, ptr_clone; + struct ethhdr *hdr; + + bpf_dynptr_from_skb((struct __sk_buff *)skb, 0, &ptr); + + bpf_dynptr_clone(&ptr, &ptr_clone); + + hdr = bpf_dynptr_slice(&ptr_clone, 0, NULL, sizeof(*hdr)); + if (!hdr) { + bpf_qdisc_skb_drop(skb, to_free); + return NET_XMIT_DROP; + } + + *(int *)&ptr = 0; + + proto = hdr->h_proto; + + bpf_qdisc_skb_drop(skb, to_free); + + return NET_XMIT_DROP; +} + +SEC("struct_ops") +__auxiliary +struct sk_buff *BPF_PROG(bpf_qdisc_test_dequeue, struct Qdisc *sch) +{ + return NULL; +} + +SEC("struct_ops") +__auxiliary +int BPF_PROG(bpf_qdisc_test_init, struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + return 0; +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_reset, struct Qdisc *sch) +{ +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_destroy, struct Qdisc *sch) +{ +} + +SEC(".struct_ops") +struct Qdisc_ops test = { + .enqueue = (void *)dynptr_use_after_invalidate_clone, + .dequeue = (void *)bpf_qdisc_test_dequeue, + .init = (void *)bpf_qdisc_test_init, + .reset = (void *)bpf_qdisc_test_reset, + .destroy = (void *)bpf_qdisc_test_destroy, + .id = "bpf_qdisc_test", +}; diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr.c b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr.c new file mode 100644 index 000000000000..1d96f7987a3f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf_experimental.h" +#include "bpf_qdisc_common.h" +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +int proto; + +SEC("struct_ops") +__failure __msg("Expected an initialized dynptr as R1") +int BPF_PROG(invalid_dynptr, struct sk_buff *skb, struct Qdisc *sch, + struct bpf_sk_buff_ptr *to_free) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + + bpf_dynptr_from_skb((struct __sk_buff *)skb, 0, &ptr); + + bpf_qdisc_skb_drop(skb, to_free); + + hdr = bpf_dynptr_slice(&ptr, 0, NULL, sizeof(*hdr)); + if (!hdr) + return NET_XMIT_DROP; + + proto = hdr->h_proto; + + return NET_XMIT_DROP; +} + +SEC("struct_ops") +__auxiliary +struct sk_buff *BPF_PROG(bpf_qdisc_test_dequeue, struct Qdisc *sch) +{ + return NULL; +} + +SEC("struct_ops") +__auxiliary +int BPF_PROG(bpf_qdisc_test_init, struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + return 0; +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_reset, struct Qdisc *sch) +{ +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_destroy, struct Qdisc *sch) +{ +} + +SEC(".struct_ops") +struct Qdisc_ops test = { + .enqueue = (void *)invalid_dynptr, + .dequeue = (void *)bpf_qdisc_test_dequeue, + .init = (void *)bpf_qdisc_test_init, + .reset = (void *)bpf_qdisc_test_reset, + .destroy = (void *)bpf_qdisc_test_destroy, + .id = "bpf_qdisc_test", +}; diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_cross_frame.c b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_cross_frame.c new file mode 100644 index 000000000000..2e23b8593af9 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_cross_frame.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf_experimental.h" +#include "bpf_qdisc_common.h" +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +int proto; + +static __noinline int free_skb(struct sk_buff *skb) +{ + bpf_kfree_skb(skb); + return 0; +} + +SEC("struct_ops") +__failure __msg("invalid mem access 'scalar'") +int BPF_PROG(invalid_dynptr_cross_frame, struct sk_buff *skb, struct Qdisc *sch, + struct bpf_sk_buff_ptr *to_free) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + + bpf_dynptr_from_skb((struct __sk_buff *)skb, 0, &ptr); + + hdr = bpf_dynptr_slice(&ptr, 0, NULL, sizeof(*hdr)); + if (!hdr) + return NET_XMIT_DROP; + + free_skb(skb); + + proto = hdr->h_proto; + + return NET_XMIT_DROP; +} + +SEC("struct_ops") +__auxiliary +struct sk_buff *BPF_PROG(bpf_qdisc_test_dequeue, struct Qdisc *sch) +{ + return NULL; +} + +SEC("struct_ops") +__auxiliary +int BPF_PROG(bpf_qdisc_test_init, struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + return 0; +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_reset, struct Qdisc *sch) +{ +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_destroy, struct Qdisc *sch) +{ +} + +SEC(".struct_ops") +struct Qdisc_ops test = { + .enqueue = (void *)invalid_dynptr_cross_frame, + .dequeue = (void *)bpf_qdisc_test_dequeue, + .init = (void *)bpf_qdisc_test_init, + .reset = (void *)bpf_qdisc_test_reset, + .destroy = (void *)bpf_qdisc_test_destroy, + .id = "bpf_qdisc_test", +}; diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_slice.c b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_slice.c new file mode 100644 index 000000000000..731216c4e45a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_fail__invalid_dynptr_slice.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include "bpf_experimental.h" +#include "bpf_qdisc_common.h" +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +int proto; + +SEC("struct_ops") +__failure __msg("invalid mem access 'scalar'") +int BPF_PROG(invalid_dynptr_slice, struct sk_buff *skb, struct Qdisc *sch, + struct bpf_sk_buff_ptr *to_free) +{ + struct bpf_dynptr ptr; + struct ethhdr *hdr; + + bpf_dynptr_from_skb((struct __sk_buff *)skb, 0, &ptr); + + hdr = bpf_dynptr_slice(&ptr, 0, NULL, sizeof(*hdr)); + if (!hdr) { + bpf_qdisc_skb_drop(skb, to_free); + return NET_XMIT_DROP; + } + + bpf_qdisc_skb_drop(skb, to_free); + + proto = hdr->h_proto; + + return NET_XMIT_DROP; +} + +SEC("struct_ops") +__auxiliary +struct sk_buff *BPF_PROG(bpf_qdisc_test_dequeue, struct Qdisc *sch) +{ + return NULL; +} + +SEC("struct_ops") +__auxiliary +int BPF_PROG(bpf_qdisc_test_init, struct Qdisc *sch, struct nlattr *opt, + struct netlink_ext_ack *extack) +{ + return 0; +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_reset, struct Qdisc *sch) +{ +} + +SEC("struct_ops") +__auxiliary +void BPF_PROG(bpf_qdisc_test_destroy, struct Qdisc *sch) +{ +} + +SEC(".struct_ops") +struct Qdisc_ops test = { + .enqueue = (void *)invalid_dynptr_slice, + .dequeue = (void *)bpf_qdisc_test_dequeue, + .init = (void *)bpf_qdisc_test_init, + .reset = (void *)bpf_qdisc_test_reset, + .destroy = (void *)bpf_qdisc_test_destroy, + .id = "bpf_qdisc_test", +}; diff --git a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c index a875ba8e5007..d0d65d6d450c 100644 --- a/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c +++ b/tools/testing/selftests/bpf/progs/cgrp_kfunc_failure.c @@ -154,7 +154,7 @@ int BPF_PROG(cgrp_kfunc_xchg_unreleased, struct cgroup *cgrp, const char *path) } SEC("tp_btf/cgroup_mkdir") -__failure __msg("must be referenced or trusted") +__failure __msg("release kfunc bpf_cgroup_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(cgrp_kfunc_rcu_get_release, struct cgroup *cgrp, const char *path) { struct cgroup *kptr; @@ -191,7 +191,7 @@ int BPF_PROG(cgrp_kfunc_release_untrusted, struct cgroup *cgrp, const char *path } SEC("tp_btf/cgroup_mkdir") -__failure __msg("R1 pointer type STRUCT cgroup must point") +__failure __msg("release kfunc bpf_cgroup_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(cgrp_kfunc_release_fp, struct cgroup *cgrp, const char *path) { struct cgroup *acquired = (struct cgroup *)&path; @@ -237,7 +237,7 @@ int BPF_PROG(cgrp_kfunc_release_null, struct cgroup *cgrp, const char *path) } SEC("tp_btf/cgroup_mkdir") -__failure __msg("release kernel function bpf_cgroup_release expects") +__failure __msg("release kfunc bpf_cgroup_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(cgrp_kfunc_release_unacquired, struct cgroup *cgrp, const char *path) { /* Cannot release trusted cgroup pointer which was not acquired. */ diff --git a/tools/testing/selftests/bpf/progs/dynptr_fail.c b/tools/testing/selftests/bpf/progs/dynptr_fail.c index dbd97add5a5a..344fb2aa0813 100644 --- a/tools/testing/selftests/bpf/progs/dynptr_fail.c +++ b/tools/testing/selftests/bpf/progs/dynptr_fail.c @@ -78,7 +78,7 @@ static int get_map_val_dynptr(struct bpf_dynptr *ptr) * bpf_ringbuf_submit/discard_dynptr call */ SEC("?raw_tp") -__failure __msg("Unreleased reference id=2") +__failure __msg("Unreleased reference id=1") int ringbuf_missing_release1(void *ctx) { struct bpf_dynptr ptr = {}; @@ -91,7 +91,7 @@ int ringbuf_missing_release1(void *ctx) } SEC("?raw_tp") -__failure __msg("Unreleased reference id=4") +__failure __msg("Unreleased reference id=3") int ringbuf_missing_release2(void *ctx) { struct bpf_dynptr ptr1, ptr2; @@ -136,7 +136,7 @@ int ringbuf_missing_release_callback(void *ctx) /* Can't call bpf_ringbuf_submit/discard_dynptr on a non-initialized dynptr */ SEC("?raw_tp") -__failure __msg("arg 1 is an unacquired reference") +__failure __msg("Expected an initialized dynptr as R1") int ringbuf_release_uninit_dynptr(void *ctx) { struct bpf_dynptr ptr; @@ -650,7 +650,7 @@ int invalid_offset(void *ctx) /* Can't release a dynptr twice */ SEC("?raw_tp") -__failure __msg("arg 1 is an unacquired reference") +__failure __msg("Expected an initialized dynptr as R1") int release_twice(void *ctx) { struct bpf_dynptr ptr; @@ -677,7 +677,7 @@ static int release_twice_callback_fn(__u32 index, void *data) * within a callback function, fails */ SEC("?raw_tp") -__failure __msg("arg 1 is an unacquired reference") +__failure __msg("Expected an initialized dynptr as R1") int release_twice_callback(void *ctx) { struct bpf_dynptr ptr; @@ -705,6 +705,48 @@ int dynptr_from_mem_invalid_api(void *ctx) return 0; } +/* Cannot create dynptr from dynptr data */ +SEC("?raw_tp") +__failure __msg("Unsupported reg type mem for bpf_dynptr_from_mem data") +int dynptr_from_dynptr_data(void *ctx) +{ + struct bpf_dynptr ptr, ptr2; + __u8 *data; + + if (get_map_val_dynptr(&ptr)) + return 0; + + data = bpf_dynptr_data(&ptr, 0, sizeof(__u32)); + if (!data) + return 0; + + /* this should fail */ + bpf_dynptr_from_mem(data, sizeof(__u32), 0, &ptr2); + + return 0; +} + +/* Cannot create dynptr from dynptr slice */ +SEC("?tc") +__failure __msg("Unsupported reg type mem for bpf_dynptr_from_mem data") +int dynptr_from_dynptr_slice(struct __sk_buff *skb) +{ + struct bpf_dynptr ptr, ptr2; + struct ethhdr *hdr; + char buffer[sizeof(*hdr)] = {}; + + bpf_dynptr_from_skb(skb, 0, &ptr); + + hdr = bpf_dynptr_slice_rdwr(&ptr, 0, buffer, sizeof(buffer)); + if (!hdr) + return SK_DROP; + + /* this should fail */ + bpf_dynptr_from_mem(hdr, sizeof(*hdr), 0, &ptr2); + + return SK_PASS; +} + SEC("?tc") __failure __msg("cannot overwrite referenced dynptr") __log_level(2) int dynptr_pruning_overwrite(struct __sk_buff *ctx) diff --git a/tools/testing/selftests/bpf/progs/file_reader_fail.c b/tools/testing/selftests/bpf/progs/file_reader_fail.c index 0739620dea8a..d5fae5e4cf9a 100644 --- a/tools/testing/selftests/bpf/progs/file_reader_fail.c +++ b/tools/testing/selftests/bpf/progs/file_reader_fail.c @@ -50,3 +50,63 @@ int xdp_no_dynptr_type(struct xdp_md *xdp) bpf_dynptr_file_discard(&dynptr); return 0; } + +SEC("lsm/file_open") +__failure +__msg("Leaking reference id={{[0-9]+}} alloc_insn={{[0-9]+}}. Release it first.") +int use_file_dynptr_after_put_file(void *ctx) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct file *file = bpf_get_task_exe_file(task); + struct bpf_dynptr dynptr; + char buf[64]; + + if (!file) + return 0; + + if (bpf_dynptr_from_file(file, 0, &dynptr)) + goto out; + + /* this should fail - file dynptr should be discarded first to prevent resource leak */ + bpf_put_file(file); + + bpf_dynptr_read(buf, sizeof(buf), &dynptr, 0, 0); + return 0; + +out: + bpf_dynptr_file_discard(&dynptr); + bpf_put_file(file); + return 0; +} + +SEC("lsm/file_open") +__failure +__msg("Leaking reference id={{[0-9]+}} alloc_insn={{[0-9]+}}. Release it first.") +int use_file_dynptr_slice_after_put_file(void *ctx) +{ + struct task_struct *task = bpf_get_current_task_btf(); + struct file *file = bpf_get_task_exe_file(task); + struct bpf_dynptr dynptr; + char *data; + + if (!file) + return 0; + + if (bpf_dynptr_from_file(file, 0, &dynptr)) + goto out; + + data = bpf_dynptr_data(&dynptr, 0, 1); + if (!data) + goto out; + + /* this should fail - file dynptr should be discarded first to prevent resource leak */ + bpf_put_file(file); + + *data = 'x'; + return 0; + +out: + bpf_dynptr_file_discard(&dynptr); + bpf_put_file(file); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/iters_state_safety.c b/tools/testing/selftests/bpf/progs/iters_state_safety.c index af8f9ec1ea98..646026430e9b 100644 --- a/tools/testing/selftests/bpf/progs/iters_state_safety.c +++ b/tools/testing/selftests/bpf/progs/iters_state_safety.c @@ -30,7 +30,7 @@ int force_clang_to_emit_btf_for_externs(void *ctx) SEC("?raw_tp") __success __log_level(2) -__msg("fp-8=iter_num(ref_id=1,state=active,depth=0)") +__msg("fp-8=iter_num(id=1,state=active,depth=0)") int create_and_destroy(void *ctx) { struct bpf_iter_num iter; @@ -196,7 +196,7 @@ int leak_iter_from_subprog_fail(void *ctx) SEC("?raw_tp") __success __log_level(2) -__msg("fp-8=iter_num(ref_id=1,state=active,depth=0)") +__msg("fp-8=iter_num(id=1,state=active,depth=0)") int valid_stack_reuse(void *ctx) { struct bpf_iter_num iter; diff --git a/tools/testing/selftests/bpf/progs/iters_testmod_seq.c b/tools/testing/selftests/bpf/progs/iters_testmod_seq.c index 9b760dac333e..d00888f6687a 100644 --- a/tools/testing/selftests/bpf/progs/iters_testmod_seq.c +++ b/tools/testing/selftests/bpf/progs/iters_testmod_seq.c @@ -20,8 +20,8 @@ __s64 res_empty; SEC("raw_tp/sys_enter") __success __log_level(2) -__msg("fp-16=iter_testmod_seq(ref_id=1,state=active,depth=0)") -__msg("fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=active,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=drained,depth=0)") __msg("call bpf_iter_testmod_seq_destroy") int testmod_seq_empty(const void *ctx) { @@ -38,8 +38,8 @@ __s64 res_full; SEC("raw_tp/sys_enter") __success __log_level(2) -__msg("fp-16=iter_testmod_seq(ref_id=1,state=active,depth=0)") -__msg("fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=active,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=drained,depth=0)") __msg("call bpf_iter_testmod_seq_destroy") int testmod_seq_full(const void *ctx) { @@ -58,8 +58,8 @@ static volatile int zero = 0; SEC("raw_tp/sys_enter") __success __log_level(2) -__msg("fp-16=iter_testmod_seq(ref_id=1,state=active,depth=0)") -__msg("fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=active,depth=0)") +__msg("fp-16=iter_testmod_seq(id=1,state=drained,depth=0)") __msg("call bpf_iter_testmod_seq_destroy") int testmod_seq_truncated(const void *ctx) { diff --git a/tools/testing/selftests/bpf/progs/map_kptr_fail.c b/tools/testing/selftests/bpf/progs/map_kptr_fail.c index 8f36e74fd8f9..f11848dfa78f 100644 --- a/tools/testing/selftests/bpf/progs/map_kptr_fail.c +++ b/tools/testing/selftests/bpf/progs/map_kptr_fail.c @@ -252,7 +252,7 @@ int reject_untrusted_store_to_ref(struct __sk_buff *ctx) } SEC("?tc") -__failure __msg("R2 must be referenced") +__failure __msg("release helper bpf_kptr_xchg expects referenced PTR_TO_BTF_ID passed to R2") int reject_untrusted_xchg(struct __sk_buff *ctx) { struct prog_test_ref_kfunc *p; diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_failure.c b/tools/testing/selftests/bpf/progs/task_kfunc_failure.c index 41047d81ec42..8e947d445f8e 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_failure.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_failure.c @@ -178,7 +178,7 @@ int BPF_PROG(task_kfunc_release_untrusted, struct task_struct *task, u64 clone_f } SEC("tp_btf/task_newtask") -__failure __msg("R1 pointer type STRUCT task_struct must point") +__failure __msg("release kfunc bpf_task_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(task_kfunc_release_fp, struct task_struct *task, u64 clone_flags) { struct task_struct *acquired = (struct task_struct *)&clone_flags; @@ -224,7 +224,7 @@ int BPF_PROG(task_kfunc_release_null, struct task_struct *task, u64 clone_flags) } SEC("tp_btf/task_newtask") -__failure __msg("release kernel function bpf_task_release expects") +__failure __msg("release kfunc bpf_task_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(task_kfunc_release_unacquired, struct task_struct *task, u64 clone_flags) { /* Cannot release trusted task pointer which was not acquired. */ @@ -313,7 +313,7 @@ int BPF_PROG(task_access_comm4, struct task_struct *task, const char *buf, bool } SEC("tp_btf/task_newtask") -__failure __msg("R1 must be referenced or trusted") +__failure __msg("release kfunc bpf_task_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(task_kfunc_release_in_map, struct task_struct *task, u64 clone_flags) { struct task_struct *local; diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c index 21bb7da90ea5..0efafa927a3d 100644 --- a/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c +++ b/tools/testing/selftests/bpf/progs/test_ringbuf_map_key.c @@ -35,7 +35,7 @@ SEC("fentry/" SYS_PREFIX "sys_getpgid") int test_ringbuf_mem_map_key(void *ctx) { int cur_pid = bpf_get_current_pid_tgid() >> 32; - struct sample *sample, sample_copy; + struct sample *sample; int *lookup_val; if (cur_pid != pid) @@ -55,16 +55,11 @@ int test_ringbuf_mem_map_key(void *ctx) lookup_val = (int *)bpf_map_lookup_elem(&hash_map, sample); __sink(lookup_val); - /* workaround - memcpy is necessary so that verifier doesn't - * complain with: - * verifier internal error: more than one arg with ref_obj_id R3 - * when trying to do bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY); - * + /* * Since bpf_map_lookup_elem above uses 'sample' as key, test using * sample field as value below */ - __builtin_memcpy(&sample_copy, sample, sizeof(struct sample)); - bpf_map_update_elem(&hash_map, &sample_copy, &sample->seq, BPF_ANY); + bpf_map_update_elem(&hash_map, sample, &sample->seq, BPF_ANY); bpf_ringbuf_submit(sample, 0); return 0; diff --git a/tools/testing/selftests/bpf/progs/user_ringbuf_fail.c b/tools/testing/selftests/bpf/progs/user_ringbuf_fail.c index 54de0389f878..c0d0422b8030 100644 --- a/tools/testing/selftests/bpf/progs/user_ringbuf_fail.c +++ b/tools/testing/selftests/bpf/progs/user_ringbuf_fail.c @@ -146,7 +146,7 @@ try_discard_dynptr(struct bpf_dynptr *dynptr, void *context) * not be able to read past the end of the pointer. */ SEC("?raw_tp") -__failure __msg("cannot release unowned const bpf_dynptr") +__failure __msg("CONST_PTR_TO_DYNPTR cannot be released") int user_ringbuf_callback_discard_dynptr(void *ctx) { bpf_user_ringbuf_drain(&user_ringbuf, try_discard_dynptr, NULL, 0); @@ -166,7 +166,7 @@ try_submit_dynptr(struct bpf_dynptr *dynptr, void *context) * not be able to read past the end of the pointer. */ SEC("?raw_tp") -__failure __msg("cannot release unowned const bpf_dynptr") +__failure __msg("CONST_PTR_TO_DYNPTR cannot be released") int user_ringbuf_callback_submit_dynptr(void *ctx) { bpf_user_ringbuf_drain(&user_ringbuf, try_submit_dynptr, NULL, 0); diff --git a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c index e7dae0cf9c17..ea273e152209 100644 --- a/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c +++ b/tools/testing/selftests/bpf/progs/verifier_global_ptr_args.c @@ -153,7 +153,7 @@ __weak int subprog_trusted_destroy(struct task_struct *task __arg_trusted) SEC("?tp_btf/task_newtask") __failure __log_level(2) -__msg("release kernel function bpf_task_release expects refcounted PTR_TO_BTF_ID") +__msg("release kfunc bpf_task_release expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(trusted_destroy_fail, struct task_struct *task, u64 clone_flags) { return subprog_trusted_destroy(task); diff --git a/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c b/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c index 139f70bb3595..199ad18f8eb5 100644 --- a/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c +++ b/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c @@ -1288,7 +1288,7 @@ l1_%=: r1 = r6; \ SEC("tc") __description("reference tracking: bpf_sk_release(listen_sk)") -__failure __msg("R1 must be referenced when passed to release function") +__failure __msg("release helper bpf_sk_release expects referenced PTR_TO_BTF_ID passed to R1") __naked void bpf_sk_release_listen_sk(void) { asm volatile ( diff --git a/tools/testing/selftests/bpf/progs/verifier_sock.c b/tools/testing/selftests/bpf/progs/verifier_sock.c index a2132c72d3b8..9f680cf44512 100644 --- a/tools/testing/selftests/bpf/progs/verifier_sock.c +++ b/tools/testing/selftests/bpf/progs/verifier_sock.c @@ -603,7 +603,7 @@ l2_%=: r0 = *(u32*)(r0 + %[bpf_tcp_sock_snd_cwnd]); \ SEC("tc") __description("bpf_sk_release(skb->sk)") -__failure __msg("R1 must be referenced when passed to release function") +__failure __msg("release helper bpf_sk_release expects referenced PTR_TO_BTF_ID passed to R1") __naked void bpf_sk_release_skb_sk(void) { asm volatile (" \ @@ -620,7 +620,7 @@ l0_%=: r0 = 0; \ SEC("tc") __description("bpf_sk_release(bpf_sk_fullsock(skb->sk))") -__failure __msg("R1 must be referenced when passed to release function") +__failure __msg("release helper bpf_sk_release expects referenced PTR_TO_BTF_ID passed to R1") __naked void bpf_sk_fullsock_skb_sk(void) { asm volatile (" \ @@ -644,7 +644,7 @@ l1_%=: r1 = r0; \ SEC("tc") __description("bpf_sk_release(bpf_tcp_sock(skb->sk))") -__failure __msg("R1 must be referenced when passed to release function") +__failure __msg("release helper bpf_sk_release expects referenced PTR_TO_BTF_ID passed to R1") __naked void bpf_tcp_sock_skb_sk(void) { asm volatile (" \ diff --git a/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c b/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c index 0990de076844..2870738d93f7 100644 --- a/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c +++ b/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c @@ -80,7 +80,7 @@ int BPF_PROG(get_task_exe_file_kfunc_unreleased) } SEC("lsm.s/file_open") -__failure __msg("release kernel function bpf_put_file expects") +__failure __msg("release kfunc bpf_put_file expects referenced PTR_TO_BTF_ID passed to R1") int BPF_PROG(put_file_kfunc_unacquired, struct file *file) { /* Can't release an unacquired pointer. */ diff --git a/tools/testing/selftests/bpf/progs/wakeup_source_fail.c b/tools/testing/selftests/bpf/progs/wakeup_source_fail.c index b8bbb61d4d4e..d4d0f1610853 100644 --- a/tools/testing/selftests/bpf/progs/wakeup_source_fail.c +++ b/tools/testing/selftests/bpf/progs/wakeup_source_fail.c @@ -42,7 +42,7 @@ int wakeup_source_access_lock_fields(void *ctx) } SEC("syscall") -__failure __msg("type=scalar expected=fp") +__failure __msg("release kfunc bpf_wakeup_sources_read_unlock expects referenced PTR_TO_BTF_ID passed to R1") int wakeup_source_unlock_no_lock(void *ctx) { struct bpf_ws_lock *lock = (void *)0x1; diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index 0bb4337552c8..42d523a21a43 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -2410,27 +2410,3 @@ .errstr_unpriv = "", .prog_type = BPF_PROG_TYPE_CGROUP_SKB, }, -{ - "calls: several args with ref_obj_id", - .insns = { - /* Reserve at least sizeof(struct iphdr) bytes in the ring buffer. - * With a smaller size, the verifier would reject the call to - * bpf_tcp_raw_gen_syncookie_ipv4 before we can reach the - * ref_obj_id error. - */ - BPF_MOV64_IMM(BPF_REG_2, 20), - BPF_MOV64_IMM(BPF_REG_3, 0), - BPF_LD_MAP_FD(BPF_REG_1, 0), - BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve), - /* if r0 == 0 goto */ - BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), - BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), - BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), - BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_tcp_raw_gen_syncookie_ipv4), - BPF_EXIT_INSN(), - }, - .fixup_map_ringbuf = { 2 }, - .result = REJECT, - .errstr = "more than one arg with ref_obj_id", - .prog_type = BPF_PROG_TYPE_SCHED_CLS, -},