diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 1211 |
1 files changed, 952 insertions, 259 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a39eedecc93a..aedac2ac02b9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -187,6 +187,9 @@ struct bpf_verifier_stack_elem { POISON_POINTER_DELTA)) #define BPF_MAP_PTR(X) ((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV)) +static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx); +static int release_reference(struct bpf_verifier_env *env, int ref_obj_id); + static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux) { return BPF_MAP_PTR(aux->map_ptr_state) == BPF_MAP_PTR_POISON; @@ -245,6 +248,7 @@ struct bpf_call_arg_meta { struct bpf_map *map_ptr; bool raw_mode; bool pkt_access; + u8 release_regno; int regno; int access_size; int mem_size; @@ -257,6 +261,8 @@ struct bpf_call_arg_meta { struct btf *ret_btf; u32 ret_btf_id; u32 subprogno; + struct bpf_map_value_off_desc *kptr_off_desc; + u8 uninit_dynptr_regno; }; struct btf *btf_vmlinux; @@ -452,7 +458,8 @@ static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type) { return base_type(type) == PTR_TO_SOCKET || base_type(type) == PTR_TO_TCP_SOCK || - base_type(type) == PTR_TO_MEM; + base_type(type) == PTR_TO_MEM || + base_type(type) == PTR_TO_BTF_ID; } static bool type_is_rdonly_mem(u32 type) @@ -470,17 +477,6 @@ static bool type_may_be_null(u32 type) return type & PTR_MAYBE_NULL; } -/* Determine whether the function releases some resources allocated by another - * function call. The first reference type argument will be assumed to be - * released by release_reference(). - */ -static bool is_release_function(enum bpf_func_id func_id) -{ - return func_id == BPF_FUNC_sk_release || - func_id == BPF_FUNC_ringbuf_submit || - func_id == BPF_FUNC_ringbuf_discard; -} - static bool may_be_acquire_function(enum bpf_func_id func_id) { return func_id == BPF_FUNC_sk_lookup_tcp || @@ -498,7 +494,8 @@ static bool is_acquire_function(enum bpf_func_id func_id, if (func_id == BPF_FUNC_sk_lookup_tcp || func_id == BPF_FUNC_sk_lookup_udp || func_id == BPF_FUNC_skc_lookup_tcp || - func_id == BPF_FUNC_ringbuf_reserve) + func_id == BPF_FUNC_ringbuf_reserve || + func_id == BPF_FUNC_kptr_xchg) return true; if (func_id == BPF_FUNC_map_lookup_elem && @@ -516,6 +513,7 @@ static bool is_ptr_cast_function(enum bpf_func_id func_id) func_id == BPF_FUNC_skc_to_tcp_sock || func_id == BPF_FUNC_skc_to_tcp6_sock || func_id == BPF_FUNC_skc_to_udp6_sock || + func_id == BPF_FUNC_skc_to_mptcp_sock || func_id == BPF_FUNC_skc_to_tcp_timewait_sock || func_id == BPF_FUNC_skc_to_tcp_request_sock; } @@ -535,10 +533,10 @@ static bool is_cmpxchg_insn(const struct bpf_insn *insn) static const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type) { - char postfix[16] = {0}, prefix[16] = {0}; + char postfix[16] = {0}, prefix[32] = {0}; static const char * const str[] = { [NOT_INIT] = "?", - [SCALAR_VALUE] = "inv", + [SCALAR_VALUE] = "scalar", [PTR_TO_CTX] = "ctx", [CONST_PTR_TO_MAP] = "map_ptr", [PTR_TO_MAP_VALUE] = "map_value", @@ -553,7 +551,6 @@ static const char *reg_type_str(struct bpf_verifier_env *env, [PTR_TO_TP_BUFFER] = "tp_buffer", [PTR_TO_XDP_SOCK] = "xdp_sock", [PTR_TO_BTF_ID] = "ptr_", - [PTR_TO_PERCPU_BTF_ID] = "percpu_ptr_", [PTR_TO_MEM] = "mem", [PTR_TO_BUF] = "buf", [PTR_TO_FUNC] = "func", @@ -561,17 +558,22 @@ static const char *reg_type_str(struct bpf_verifier_env *env, }; if (type & PTR_MAYBE_NULL) { - if (base_type(type) == PTR_TO_BTF_ID || - base_type(type) == PTR_TO_PERCPU_BTF_ID) + if (base_type(type) == PTR_TO_BTF_ID) strncpy(postfix, "or_null_", 16); else strncpy(postfix, "_or_null", 16); } if (type & MEM_RDONLY) - strncpy(prefix, "rdonly_", 16); + strncpy(prefix, "rdonly_", 32); if (type & MEM_ALLOC) - strncpy(prefix, "alloc_", 16); + strncpy(prefix, "alloc_", 32); + if (type & MEM_USER) + strncpy(prefix, "user_", 32); + if (type & MEM_PERCPU) + strncpy(prefix, "percpu_", 32); + if (type & PTR_UNTRUSTED) + strncpy(prefix, "untrusted_", 32); snprintf(env->type_str_buf, TYPE_STR_BUF_LEN, "%s%s%s", prefix, str[base_type(type)], postfix); @@ -583,6 +585,7 @@ static char slot_type_char[] = { [STACK_SPILL] = 'r', [STACK_MISC] = 'm', [STACK_ZERO] = '0', + [STACK_DYNPTR] = 'd', }; static void print_liveness(struct bpf_verifier_env *env, @@ -598,6 +601,25 @@ static void print_liveness(struct bpf_verifier_env *env, verbose(env, "D"); } +static int get_spi(s32 off) +{ + return (-off - 1) / BPF_REG_SIZE; +} + +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; + + /* We need to check that slots between [spi - nr_slots + 1, spi] are + * within [0, allocated_stack). + * + * Please note that the spi grows downwards. For example, a dynptr + * takes the size of two stack slots; the first slot will be at + * spi and the second slot will be at spi - 1. + */ + return spi - nr_slots + 1 >= 0 && spi < allocated_slots; +} + static struct bpf_func_state *func(struct bpf_verifier_env *env, const struct bpf_reg_state *reg) { @@ -649,6 +671,132 @@ static void mark_verifier_state_scratched(struct bpf_verifier_env *env) env->scratched_stack_slots = ~0ULL; } +static enum bpf_dynptr_type arg_to_dynptr_type(enum bpf_arg_type arg_type) +{ + switch (arg_type & DYNPTR_TYPE_FLAG_MASK) { + case DYNPTR_TYPE_LOCAL: + return BPF_DYNPTR_TYPE_LOCAL; + case DYNPTR_TYPE_RINGBUF: + return BPF_DYNPTR_TYPE_RINGBUF; + default: + return BPF_DYNPTR_TYPE_INVALID; + } +} + +static bool dynptr_type_refcounted(enum bpf_dynptr_type type) +{ + return type == BPF_DYNPTR_TYPE_RINGBUF; +} + +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) +{ + struct bpf_func_state *state = func(env, reg); + enum bpf_dynptr_type type; + int spi, i, id; + + spi = get_spi(reg->off); + + if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS)) + return -EINVAL; + + for (i = 0; i < BPF_REG_SIZE; i++) { + state->stack[spi].slot_type[i] = STACK_DYNPTR; + state->stack[spi - 1].slot_type[i] = STACK_DYNPTR; + } + + type = arg_to_dynptr_type(arg_type); + if (type == BPF_DYNPTR_TYPE_INVALID) + return -EINVAL; + + state->stack[spi].spilled_ptr.dynptr.first_slot = true; + state->stack[spi].spilled_ptr.dynptr.type = type; + state->stack[spi - 1].spilled_ptr.dynptr.type = type; + + if (dynptr_type_refcounted(type)) { + /* The id is used to track proper releasing */ + id = acquire_reference_state(env, insn_idx); + if (id < 0) + return id; + + state->stack[spi].spilled_ptr.id = id; + state->stack[spi - 1].spilled_ptr.id = id; + } + + return 0; +} + +static int unmark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + int spi, i; + + spi = get_spi(reg->off); + + if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS)) + return -EINVAL; + + 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; + } + + /* Invalidate any slices associated with this dynptr */ + if (dynptr_type_refcounted(state->stack[spi].spilled_ptr.dynptr.type)) { + release_reference(env, state->stack[spi].spilled_ptr.id); + state->stack[spi].spilled_ptr.id = 0; + state->stack[spi - 1].spilled_ptr.id = 0; + } + + state->stack[spi].spilled_ptr.dynptr.first_slot = false; + state->stack[spi].spilled_ptr.dynptr.type = 0; + state->stack[spi - 1].spilled_ptr.dynptr.type = 0; + + return 0; +} + +static bool is_dynptr_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + int spi = get_spi(reg->off); + int i; + + if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS)) + return true; + + for (i = 0; i < BPF_REG_SIZE; i++) { + if (state->stack[spi].slot_type[i] == STACK_DYNPTR || + state->stack[spi - 1].slot_type[i] == STACK_DYNPTR) + return false; + } + + return true; +} + +static bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + enum bpf_arg_type arg_type) +{ + struct bpf_func_state *state = func(env, reg); + int spi = get_spi(reg->off); + int i; + + if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS) || + !state->stack[spi].spilled_ptr.dynptr.first_slot) + return false; + + for (i = 0; i < BPF_REG_SIZE; i++) { + if (state->stack[spi].slot_type[i] != STACK_DYNPTR || + state->stack[spi - 1].slot_type[i] != STACK_DYNPTR) + return false; + } + + /* ARG_PTR_TO_DYNPTR takes any type of dynptr */ + if (arg_type == ARG_PTR_TO_DYNPTR) + return true; + + return state->stack[spi].spilled_ptr.dynptr.type == arg_to_dynptr_type(arg_type); +} + /* The reg state of a pointer or a bounded scalar was saved when * it was spilled to the stack. */ @@ -682,74 +830,79 @@ static void print_verifier_state(struct bpf_verifier_env *env, continue; verbose(env, " R%d", i); print_liveness(env, reg->live); - verbose(env, "=%s", reg_type_str(env, t)); + verbose(env, "="); if (t == SCALAR_VALUE && reg->precise) verbose(env, "P"); if ((t == SCALAR_VALUE || t == PTR_TO_STACK) && tnum_is_const(reg->var_off)) { /* reg->off should be 0 for SCALAR_VALUE */ + verbose(env, "%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t)); verbose(env, "%lld", reg->var_off.value + reg->off); } else { - if (base_type(t) == PTR_TO_BTF_ID || - base_type(t) == PTR_TO_PERCPU_BTF_ID) + const char *sep = ""; + + verbose(env, "%s", reg_type_str(env, t)); + if (base_type(t) == PTR_TO_BTF_ID) verbose(env, "%s", kernel_type_name(reg->btf, reg->btf_id)); - verbose(env, "(id=%d", reg->id); - if (reg_type_may_be_refcounted_or_null(t)) - verbose(env, ",ref_obj_id=%d", reg->ref_obj_id); + verbose(env, "("); +/* + * _a stands for append, was shortened to avoid multiline statements below. + * This macro is used to output a comma separated list of attributes. + */ +#define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, __VA_ARGS__); sep = ","; }) + + if (reg->id) + verbose_a("id=%d", reg->id); + if (reg_type_may_be_refcounted_or_null(t) && reg->ref_obj_id) + verbose_a("ref_obj_id=%d", reg->ref_obj_id); if (t != SCALAR_VALUE) - verbose(env, ",off=%d", reg->off); + verbose_a("off=%d", reg->off); if (type_is_pkt_pointer(t)) - verbose(env, ",r=%d", reg->range); + verbose_a("r=%d", reg->range); else if (base_type(t) == CONST_PTR_TO_MAP || base_type(t) == PTR_TO_MAP_KEY || base_type(t) == PTR_TO_MAP_VALUE) - verbose(env, ",ks=%d,vs=%d", - reg->map_ptr->key_size, - reg->map_ptr->value_size); + verbose_a("ks=%d,vs=%d", + reg->map_ptr->key_size, + reg->map_ptr->value_size); if (tnum_is_const(reg->var_off)) { /* Typically an immediate SCALAR_VALUE, but * could be a pointer whose offset is too big * for reg->off */ - verbose(env, ",imm=%llx", reg->var_off.value); + verbose_a("imm=%llx", reg->var_off.value); } else { if (reg->smin_value != reg->umin_value && reg->smin_value != S64_MIN) - verbose(env, ",smin_value=%lld", - (long long)reg->smin_value); + verbose_a("smin=%lld", (long long)reg->smin_value); if (reg->smax_value != reg->umax_value && reg->smax_value != S64_MAX) - verbose(env, ",smax_value=%lld", - (long long)reg->smax_value); + verbose_a("smax=%lld", (long long)reg->smax_value); if (reg->umin_value != 0) - verbose(env, ",umin_value=%llu", - (unsigned long long)reg->umin_value); + verbose_a("umin=%llu", (unsigned long long)reg->umin_value); if (reg->umax_value != U64_MAX) - verbose(env, ",umax_value=%llu", - (unsigned long long)reg->umax_value); + verbose_a("umax=%llu", (unsigned long long)reg->umax_value); if (!tnum_is_unknown(reg->var_off)) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose(env, ",var_off=%s", tn_buf); + verbose_a("var_off=%s", tn_buf); } if (reg->s32_min_value != reg->smin_value && reg->s32_min_value != S32_MIN) - verbose(env, ",s32_min_value=%d", - (int)(reg->s32_min_value)); + verbose_a("s32_min=%d", (int)(reg->s32_min_value)); if (reg->s32_max_value != reg->smax_value && reg->s32_max_value != S32_MAX) - verbose(env, ",s32_max_value=%d", - (int)(reg->s32_max_value)); + verbose_a("s32_max=%d", (int)(reg->s32_max_value)); if (reg->u32_min_value != reg->umin_value && reg->u32_min_value != U32_MIN) - verbose(env, ",u32_min_value=%d", - (int)(reg->u32_min_value)); + verbose_a("u32_min=%d", (int)(reg->u32_min_value)); if (reg->u32_max_value != reg->umax_value && reg->u32_max_value != U32_MAX) - verbose(env, ",u32_max_value=%d", - (int)(reg->u32_max_value)); + verbose_a("u32_max=%d", (int)(reg->u32_max_value)); } +#undef verbose_a + verbose(env, ")"); } } @@ -774,7 +927,7 @@ static void print_verifier_state(struct bpf_verifier_env *env, if (is_spilled_reg(&state->stack[i])) { reg = &state->stack[i].spilled_ptr; t = reg->type; - verbose(env, "=%s", reg_type_str(env, t)); + verbose(env, "=%s", t == SCALAR_VALUE ? "" : reg_type_str(env, t)); if (t == SCALAR_VALUE && reg->precise) verbose(env, "P"); if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) @@ -1546,14 +1699,15 @@ static void mark_reg_not_init(struct bpf_verifier_env *env, static void mark_btf_ld_reg(struct bpf_verifier_env *env, struct bpf_reg_state *regs, u32 regno, enum bpf_reg_type reg_type, - struct btf *btf, u32 btf_id) + struct btf *btf, u32 btf_id, + enum bpf_type_flag flag) { if (reg_type == SCALAR_VALUE) { mark_reg_unknown(env, regs, regno); return; } mark_reg_known_zero(env, regs, regno); - regs[regno].type = PTR_TO_BTF_ID; + regs[regno].type = PTR_TO_BTF_ID | flag; regs[regno].btf = btf; regs[regno].btf_id = btf_id; } @@ -1743,7 +1897,7 @@ find_kfunc_desc(const struct bpf_prog *prog, u32 func_id, u16 offset) } static struct btf *__find_kfunc_desc_btf(struct bpf_verifier_env *env, - s16 offset, struct module **btf_modp) + s16 offset) { struct bpf_kfunc_btf kf_btf = { .offset = offset }; struct bpf_kfunc_btf_tab *tab; @@ -1797,8 +1951,6 @@ static struct btf *__find_kfunc_desc_btf(struct bpf_verifier_env *env, sort(tab->descs, tab->nr_descs, sizeof(tab->descs[0]), kfunc_btf_cmp_by_off, NULL); } - if (btf_modp) - *btf_modp = b->module; return b->btf; } @@ -1814,9 +1966,7 @@ void bpf_free_kfunc_btf_tab(struct bpf_kfunc_btf_tab *tab) kfree(tab); } -static struct btf *find_kfunc_desc_btf(struct bpf_verifier_env *env, - u32 func_id, s16 offset, - struct module **btf_modp) +static struct btf *find_kfunc_desc_btf(struct bpf_verifier_env *env, s16 offset) { if (offset) { if (offset < 0) { @@ -1827,7 +1977,7 @@ static struct btf *find_kfunc_desc_btf(struct bpf_verifier_env *env, return ERR_PTR(-EINVAL); } - return __find_kfunc_desc_btf(env, offset, btf_modp); + return __find_kfunc_desc_btf(env, offset); } return btf_vmlinux ?: ERR_PTR(-ENOENT); } @@ -1841,6 +1991,7 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset) struct bpf_kfunc_desc *desc; const char *func_name; struct btf *desc_btf; + unsigned long call_imm; unsigned long addr; int err; @@ -1890,7 +2041,7 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset) prog_aux->kfunc_btf_tab = btf_tab; } - desc_btf = find_kfunc_desc_btf(env, func_id, offset, NULL); + desc_btf = find_kfunc_desc_btf(env, offset); if (IS_ERR(desc_btf)) { verbose(env, "failed to find BTF for kernel function\n"); return PTR_ERR(desc_btf); @@ -1925,9 +2076,17 @@ static int add_kfunc_call(struct bpf_verifier_env *env, u32 func_id, s16 offset) return -EINVAL; } + call_imm = BPF_CALL_IMM(addr); + /* Check whether or not the relative offset overflows desc->imm */ + if ((unsigned long)(s32)call_imm != call_imm) { + verbose(env, "address of kernel function %s is out of range\n", + func_name); + return -EINVAL; + } + desc = &tab->descs[tab->nr_descs++]; desc->func_id = func_id; - desc->imm = BPF_CALL_IMM(addr); + desc->imm = call_imm; desc->offset = offset; err = btf_distill_func_proto(&env->log, desc_btf, func_proto, func_name, @@ -2351,7 +2510,7 @@ static const char *disasm_kfunc_name(void *data, const struct bpf_insn *insn) if (insn->src_reg != BPF_PSEUDO_KFUNC_CALL) return NULL; - desc_btf = find_kfunc_desc_btf(data, insn->imm, insn->off, NULL); + desc_btf = find_kfunc_desc_btf(data, insn->off); if (IS_ERR(desc_btf)) return "<error>"; @@ -2767,7 +2926,6 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case PTR_TO_XDP_SOCK: case PTR_TO_BTF_ID: case PTR_TO_BUF: - case PTR_TO_PERCPU_BTF_ID: case PTR_TO_MEM: case PTR_TO_FUNC: case PTR_TO_MAP_KEY: @@ -3197,7 +3355,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env, return 0; } -enum stack_access_src { +enum bpf_access_src { ACCESS_DIRECT = 1, /* the access is performed by an instruction */ ACCESS_HELPER = 2, /* the access is performed by a helper */ }; @@ -3205,7 +3363,7 @@ enum stack_access_src { static int check_stack_range_initialized(struct bpf_verifier_env *env, int regno, int off, int access_size, bool zero_size_allowed, - enum stack_access_src type, + enum bpf_access_src type, struct bpf_call_arg_meta *meta); static struct bpf_reg_state *reg_state(struct bpf_verifier_env *env, int regno) @@ -3455,9 +3613,175 @@ static int check_mem_region_access(struct bpf_verifier_env *env, u32 regno, return 0; } +static int __check_ptr_off_reg(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno, + bool fixed_off_ok) +{ + /* Access to this pointer-typed register or passing it to a helper + * is only allowed in its original, unmodified form. + */ + + if (reg->off < 0) { + verbose(env, "negative offset %s ptr R%d off=%d disallowed\n", + reg_type_str(env, reg->type), regno, reg->off); + return -EACCES; + } + + if (!fixed_off_ok && reg->off) { + verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n", + reg_type_str(env, reg->type), regno, reg->off); + return -EACCES; + } + + if (!tnum_is_const(reg->var_off) || reg->var_off.value) { + char tn_buf[48]; + + tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); + verbose(env, "variable %s access var_off=%s disallowed\n", + reg_type_str(env, reg->type), tn_buf); + return -EACCES; + } + + return 0; +} + +int check_ptr_off_reg(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno) +{ + return __check_ptr_off_reg(env, reg, regno, false); +} + +static int map_kptr_match_type(struct bpf_verifier_env *env, + struct bpf_map_value_off_desc *off_desc, + struct bpf_reg_state *reg, u32 regno) +{ + const char *targ_name = kernel_type_name(off_desc->kptr.btf, off_desc->kptr.btf_id); + int perm_flags = PTR_MAYBE_NULL; + const char *reg_name = ""; + + /* Only unreferenced case accepts untrusted pointers */ + if (off_desc->type == BPF_KPTR_UNREF) + perm_flags |= PTR_UNTRUSTED; + + if (base_type(reg->type) != PTR_TO_BTF_ID || (type_flag(reg->type) & ~perm_flags)) + goto bad_type; + + if (!btf_is_kernel(reg->btf)) { + verbose(env, "R%d must point to kernel BTF\n", regno); + return -EINVAL; + } + /* We need to verify reg->type and reg->btf, before accessing reg->btf */ + reg_name = kernel_type_name(reg->btf, reg->btf_id); + + /* For ref_ptr case, release function check should ensure we get one + * 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, checks for + * reg->off and reg->ref_obj_id are not needed here. + */ + if (__check_ptr_off_reg(env, reg, regno, true)) + return -EACCES; + + /* A full type match is needed, as BTF can be vmlinux or module BTF, and + * we also need to take into account the reg->off. + * + * We want to support cases like: + * + * struct foo { + * struct bar br; + * struct baz bz; + * }; + * + * struct foo *v; + * v = func(); // PTR_TO_BTF_ID + * val->foo = v; // reg->off is zero, btf and btf_id match type + * val->bar = &v->br; // reg->off is still zero, but we need to retry with + * // first member type of struct after comparison fails + * val->baz = &v->bz; // reg->off is non-zero, so struct needs to be walked + * // to match type + * + * In the kptr_ref case, check_func_arg_reg_off already ensures reg->off + * is zero. We must also ensure that btf_struct_ids_match does not walk + * the struct to match type against first member of struct, i.e. reject + * second case from above. Hence, when type is BPF_KPTR_REF, we set + * strict mode to true for type match. + */ + if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, reg->off, + off_desc->kptr.btf, off_desc->kptr.btf_id, + off_desc->type == BPF_KPTR_REF)) + goto bad_type; + return 0; +bad_type: + verbose(env, "invalid kptr access, R%d type=%s%s ", regno, + reg_type_str(env, reg->type), reg_name); + verbose(env, "expected=%s%s", reg_type_str(env, PTR_TO_BTF_ID), targ_name); + if (off_desc->type == BPF_KPTR_UNREF) + verbose(env, " or %s%s\n", reg_type_str(env, PTR_TO_BTF_ID | PTR_UNTRUSTED), + targ_name); + else + verbose(env, "\n"); + return -EINVAL; +} + +static int check_map_kptr_access(struct bpf_verifier_env *env, u32 regno, + int value_regno, int insn_idx, + struct bpf_map_value_off_desc *off_desc) +{ + struct bpf_insn *insn = &env->prog->insnsi[insn_idx]; + int class = BPF_CLASS(insn->code); + struct bpf_reg_state *val_reg; + + /* Things we already checked for in check_map_access and caller: + * - Reject cases where variable offset may touch kptr + * - size of access (must be BPF_DW) + * - tnum_is_const(reg->var_off) + * - off_desc->offset == off + reg->var_off.value + */ + /* Only BPF_[LDX,STX,ST] | BPF_MEM | BPF_DW is supported */ + if (BPF_MODE(insn->code) != BPF_MEM) { + verbose(env, "kptr in map can only be accessed using BPF_MEM instruction mode\n"); + return -EACCES; + } + + /* We only allow loading referenced kptr, since it will be marked as + * untrusted, similar to unreferenced kptr. + */ + if (class != BPF_LDX && off_desc->type == BPF_KPTR_REF) { + verbose(env, "store to referenced kptr disallowed\n"); + return -EACCES; + } + + if (class == BPF_LDX) { + val_reg = reg_state(env, value_regno); + /* We can simply mark the value_regno receiving the pointer + * value from map as PTR_TO_BTF_ID, with the correct type. + */ + mark_btf_ld_reg(env, cur_regs(env), value_regno, PTR_TO_BTF_ID, off_desc->kptr.btf, + off_desc->kptr.btf_id, PTR_MAYBE_NULL | PTR_UNTRUSTED); + /* For mark_ptr_or_null_reg */ + val_reg->id = ++env->id_gen; + } else if (class == BPF_STX) { + val_reg = reg_state(env, value_regno); + if (!register_is_null(val_reg) && + map_kptr_match_type(env, off_desc, val_reg, value_regno)) + return -EACCES; + } else if (class == BPF_ST) { + if (insn->imm) { + verbose(env, "BPF_ST imm must be 0 when storing to kptr at off=%u\n", + off_desc->offset); + return -EACCES; + } + } else { + verbose(env, "kptr in map can only be accessed using BPF_LDX/BPF_STX/BPF_ST\n"); + return -EACCES; + } + return 0; +} + /* check read/write into a map element with possible variable offset */ static int check_map_access(struct bpf_verifier_env *env, u32 regno, - int off, int size, bool zero_size_allowed) + int off, int size, bool zero_size_allowed, + enum bpf_access_src src) { struct bpf_verifier_state *vstate = env->cur_state; struct bpf_func_state *state = vstate->frame[vstate->curframe]; @@ -3493,16 +3817,41 @@ static int check_map_access(struct bpf_verifier_env *env, u32 regno, return -EACCES; } } + if (map_value_has_kptrs(map)) { + struct bpf_map_value_off *tab = map->kptr_off_tab; + int i; + + for (i = 0; i < tab->nr_off; i++) { + u32 p = tab->off[i].offset; + + if (reg->smin_value + off < p + sizeof(u64) && + p < reg->umax_value + off + size) { + if (src != ACCESS_DIRECT) { + verbose(env, "kptr cannot be accessed indirectly by helper\n"); + return -EACCES; + } + if (!tnum_is_const(reg->var_off)) { + verbose(env, "kptr access cannot have variable offset\n"); + return -EACCES; + } + if (p != off + reg->var_off.value) { + verbose(env, "kptr access misaligned expected=%u off=%llu\n", + p, off + reg->var_off.value); + return -EACCES; + } + if (size != bpf_size_to_bytes(BPF_DW)) { + verbose(env, "kptr access size must be BPF_DW\n"); + return -EACCES; + } + break; + } + } + } return err; } #define MAX_PACKET_OFF 0xffff -static enum bpf_prog_type resolve_prog_type(struct bpf_prog *prog) -{ - return prog->aux->dst_prog ? prog->aux->dst_prog->type : prog->type; -} - static bool may_access_direct_pkt_data(struct bpf_verifier_env *env, const struct bpf_call_arg_meta *meta, enum bpf_access_type t) @@ -3971,38 +4320,6 @@ static int get_callee_stack_depth(struct bpf_verifier_env *env, } #endif -static int __check_ptr_off_reg(struct bpf_verifier_env *env, - const struct bpf_reg_state *reg, int regno, - bool fixed_off_ok) -{ - /* Access to this pointer-typed register or passing it to a helper - * is only allowed in its original, unmodified form. - */ - - if (!fixed_off_ok && reg->off) { - verbose(env, "dereference of modified %s ptr R%d off=%d disallowed\n", - reg_type_str(env, reg->type), regno, reg->off); - return -EACCES; - } - - if (!tnum_is_const(reg->var_off) || reg->var_off.value) { - char tn_buf[48]; - - tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); - verbose(env, "variable %s access var_off=%s disallowed\n", - reg_type_str(env, reg->type), tn_buf); - return -EACCES; - } - - return 0; -} - -int check_ptr_off_reg(struct bpf_verifier_env *env, - const struct bpf_reg_state *reg, int regno) -{ - return __check_ptr_off_reg(env, reg, regno, false); -} - static int __check_buffer_access(struct bpf_verifier_env *env, const char *buf_info, const struct bpf_reg_state *reg, @@ -4047,9 +4364,9 @@ static int check_buffer_access(struct bpf_verifier_env *env, const struct bpf_reg_state *reg, int regno, int off, int size, bool zero_size_allowed, - const char *buf_info, u32 *max_access) { + const char *buf_info = type_is_rdonly_mem(reg->type) ? "rdonly" : "rdwr"; int err; err = __check_buffer_access(env, buf_info, reg, regno, off, size); @@ -4159,6 +4476,7 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, struct bpf_reg_state *reg = regs + regno; const struct btf_type *t = btf_type_by_id(reg->btf, reg->btf_id); const char *tname = btf_name_by_offset(reg->btf, t->name_off); + enum bpf_type_flag flag = 0; u32 btf_id; int ret; @@ -4178,9 +4496,23 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, return -EACCES; } + if (reg->type & MEM_USER) { + verbose(env, + "R%d is ptr_%s access user memory: off=%d\n", + regno, tname, off); + return -EACCES; + } + + if (reg->type & MEM_PERCPU) { + verbose(env, + "R%d is ptr_%s access percpu memory: off=%d\n", + regno, tname, off); + return -EACCES; + } + if (env->ops->btf_struct_access) { ret = env->ops->btf_struct_access(&env->log, reg->btf, t, - off, size, atype, &btf_id); + off, size, atype, &btf_id, &flag); } else { if (atype != BPF_READ) { verbose(env, "only read is supported\n"); @@ -4188,14 +4520,20 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, } ret = btf_struct_access(&env->log, reg->btf, t, off, size, - atype, &btf_id); + atype, &btf_id, &flag); } if (ret < 0) return ret; + /* If this is an untrusted pointer, all pointers formed by walking it + * also inherit the untrusted flag. + */ + if (type_flag(reg->type) & PTR_UNTRUSTED) + flag |= PTR_UNTRUSTED; + if (atype == BPF_READ && value_regno >= 0) - mark_btf_ld_reg(env, regs, value_regno, ret, reg->btf, btf_id); + mark_btf_ld_reg(env, regs, value_regno, ret, reg->btf, btf_id, flag); return 0; } @@ -4208,6 +4546,7 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env, { struct bpf_reg_state *reg = regs + regno; struct bpf_map *map = reg->map_ptr; + enum bpf_type_flag flag = 0; const struct btf_type *t; const char *tname; u32 btf_id; @@ -4245,12 +4584,12 @@ static int check_ptr_to_map_access(struct bpf_verifier_env *env, return -EACCES; } - ret = btf_struct_access(&env->log, btf_vmlinux, t, off, size, atype, &btf_id); + ret = btf_struct_access(&env->log, btf_vmlinux, t, off, size, atype, &btf_id, &flag); if (ret < 0) return ret; if (value_regno >= 0) - mark_btf_ld_reg(env, regs, value_regno, ret, btf_vmlinux, btf_id); + mark_btf_ld_reg(env, regs, value_regno, ret, btf_vmlinux, btf_id, flag); return 0; } @@ -4285,7 +4624,7 @@ static int check_stack_slot_within_bounds(int off, static int check_stack_access_within_bounds( struct bpf_verifier_env *env, int regno, int off, int access_size, - enum stack_access_src src, enum bpf_access_type type) + enum bpf_access_src src, enum bpf_access_type type) { struct bpf_reg_state *regs = cur_regs(env); struct bpf_reg_state *reg = regs + regno; @@ -4381,6 +4720,8 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn if (value_regno >= 0) mark_reg_unknown(env, regs, value_regno); } else if (reg->type == PTR_TO_MAP_VALUE) { + struct bpf_map_value_off_desc *kptr_off_desc = NULL; + if (t == BPF_WRITE && value_regno >= 0 && is_pointer_value(env, value_regno)) { verbose(env, "R%d leaks addr into map\n", value_regno); @@ -4389,8 +4730,16 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn err = check_map_access_type(env, regno, off, size, t); if (err) return err; - err = check_map_access(env, regno, off, size, false); - if (!err && t == BPF_READ && value_regno >= 0) { + err = check_map_access(env, regno, off, size, false, ACCESS_DIRECT); + if (err) + return err; + if (tnum_is_const(reg->var_off)) + kptr_off_desc = bpf_map_kptr_off_contains(reg->map_ptr, + off + reg->var_off.value); + if (kptr_off_desc) { + err = check_map_kptr_access(env, regno, value_regno, insn_idx, + kptr_off_desc); + } else if (t == BPF_READ && value_regno >= 0) { struct bpf_map *map = reg->map_ptr; /* if map is read-only, track its contents as scalars */ @@ -4451,7 +4800,8 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn if (err < 0) return err; - err = check_ctx_access(env, insn_idx, off, size, t, ®_type, &btf, &btf_id); + err = check_ctx_access(env, insn_idx, off, size, t, ®_type, &btf, + &btf_id); if (err) verbose_linfo(env, insn_idx, "; "); if (!err && t == BPF_READ && value_regno >= 0) { @@ -4535,7 +4885,8 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn err = check_tp_buffer_access(env, reg, regno, off, size); if (!err && t == BPF_READ && value_regno >= 0) mark_reg_unknown(env, regs, value_regno); - } else if (reg->type == PTR_TO_BTF_ID) { + } else if (base_type(reg->type) == PTR_TO_BTF_ID && + !type_may_be_null(reg->type)) { err = check_ptr_to_btf_access(env, regs, regno, off, size, t, value_regno); } else if (reg->type == CONST_PTR_TO_MAP) { @@ -4543,7 +4894,6 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn value_regno); } else if (base_type(reg->type) == PTR_TO_BUF) { bool rdonly_mem = type_is_rdonly_mem(reg->type); - const char *buf_info; u32 *max_access; if (rdonly_mem) { @@ -4552,15 +4902,13 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn regno, reg_type_str(env, reg->type)); return -EACCES; } - buf_info = "rdonly"; max_access = &env->prog->aux->max_rdonly_access; } else { - buf_info = "rdwr"; max_access = &env->prog->aux->max_rdwr_access; } err = check_buffer_access(env, reg, regno, off, size, false, - buf_info, max_access); + max_access); if (!err && value_regno >= 0 && (rdonly_mem || t == BPF_READ)) mark_reg_unknown(env, regs, value_regno); @@ -4694,7 +5042,7 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i static int check_stack_range_initialized( struct bpf_verifier_env *env, int regno, int off, int access_size, bool zero_size_allowed, - enum stack_access_src type, struct bpf_call_arg_meta *meta) + enum bpf_access_src type, struct bpf_call_arg_meta *meta) { struct bpf_reg_state *reg = reg_state(env, regno); struct bpf_func_state *state = func(env, reg); @@ -4781,7 +5129,7 @@ static int check_stack_range_initialized( } if (is_spilled_reg(&state->stack[spi]) && - state->stack[spi].spilled_ptr.type == PTR_TO_BTF_ID) + base_type(state->stack[spi].spilled_ptr.type) == PTR_TO_BTF_ID) goto mark; if (is_spilled_reg(&state->stack[spi]) && @@ -4823,7 +5171,6 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, struct bpf_call_arg_meta *meta) { struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; - const char *buf_info; u32 *max_access; switch (base_type(reg->type)) { @@ -4832,6 +5179,11 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, return check_packet_access(env, regno, reg->off, access_size, zero_size_allowed); case PTR_TO_MAP_KEY: + if (meta && meta->raw_mode) { + verbose(env, "R%d cannot write into %s\n", regno, + reg_type_str(env, reg->type)); + return -EACCES; + } return check_mem_region_access(env, regno, reg->off, access_size, reg->map_ptr->key_size, false); case PTR_TO_MAP_VALUE: @@ -4840,25 +5192,33 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, BPF_READ)) return -EACCES; return check_map_access(env, regno, reg->off, access_size, - zero_size_allowed); + zero_size_allowed, ACCESS_HELPER); case PTR_TO_MEM: + if (type_is_rdonly_mem(reg->type)) { + if (meta && meta->raw_mode) { + verbose(env, "R%d cannot write into %s\n", regno, + reg_type_str(env, reg->type)); + return -EACCES; + } + } return check_mem_region_access(env, regno, reg->off, access_size, reg->mem_size, zero_size_allowed); case PTR_TO_BUF: if (type_is_rdonly_mem(reg->type)) { - if (meta && meta->raw_mode) + if (meta && meta->raw_mode) { + verbose(env, "R%d cannot write into %s\n", regno, + reg_type_str(env, reg->type)); return -EACCES; + } - buf_info = "rdonly"; max_access = &env->prog->aux->max_rdonly_access; } else { - buf_info = "rdwr"; max_access = &env->prog->aux->max_rdwr_access; } return check_buffer_access(env, reg, regno, reg->off, access_size, zero_size_allowed, - buf_info, max_access); + max_access); case PTR_TO_STACK: return check_stack_range_initialized( env, @@ -4877,27 +5237,119 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, } } +static int check_mem_size_reg(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, u32 regno, + bool zero_size_allowed, + struct bpf_call_arg_meta *meta) +{ + int err; + + /* This is used to refine r0 return value bounds for helpers + * that enforce this value as an upper bound on return values. + * See do_refine_retval_range() for helpers that can refine + * the return value. C type of helper is u32 so we pull register + * bound from umax_value however, if negative verifier errors + * out. Only upper bounds can be learned because retval is an + * int type and negative retvals are allowed. + */ + meta->msize_max_value = reg->umax_value; + + /* The register is SCALAR_VALUE; the access check + * happens using its boundaries. + */ + if (!tnum_is_const(reg->var_off)) + /* For unprivileged variable accesses, disable raw + * mode so that the program is required to + * initialize all the memory that the helper could + * just partially fill up. + */ + meta = NULL; + + if (reg->smin_value < 0) { + verbose(env, "R%d min value is negative, either use unsigned or 'var &= const'\n", + regno); + return -EACCES; + } + + if (reg->umin_value == 0) { + err = check_helper_mem_access(env, regno - 1, 0, + zero_size_allowed, + meta); + if (err) + return err; + } + + if (reg->umax_value >= BPF_MAX_VAR_SIZ) { + verbose(env, "R%d unbounded memory access, use 'var &= const' or 'if (var < const)'\n", + regno); + return -EACCES; + } + err = check_helper_mem_access(env, regno - 1, + reg->umax_value, + zero_size_allowed, meta); + if (!err) + err = mark_chain_precision(env, regno); + return err; +} + int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, u32 regno, u32 mem_size) { + bool may_be_null = type_may_be_null(reg->type); + struct bpf_reg_state saved_reg; + struct bpf_call_arg_meta meta; + int err; + if (register_is_null(reg)) return 0; - if (type_may_be_null(reg->type)) { - /* Assuming that the register contains a value check if the memory - * access is safe. Temporarily save and restore the register's state as - * the conversion shouldn't be visible to a caller. - */ - const struct bpf_reg_state saved_reg = *reg; - int rv; - + memset(&meta, 0, sizeof(meta)); + /* Assuming that the register contains a value check if the memory + * access is safe. Temporarily save and restore the register's state as + * the conversion shouldn't be visible to a caller. + */ + if (may_be_null) { + saved_reg = *reg; mark_ptr_not_null_reg(reg); - rv = check_helper_mem_access(env, regno, mem_size, true, NULL); + } + + err = check_helper_mem_access(env, regno, mem_size, true, &meta); + /* Check access for BPF_WRITE */ + meta.raw_mode = true; + err = err ?: check_helper_mem_access(env, regno, mem_size, true, &meta); + + if (may_be_null) *reg = saved_reg; - return rv; + + return err; +} + +int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + u32 regno) +{ + struct bpf_reg_state *mem_reg = &cur_regs(env)[regno - 1]; + bool may_be_null = type_may_be_null(mem_reg->type); + struct bpf_reg_state saved_reg; + struct bpf_call_arg_meta meta; + int err; + + WARN_ON_ONCE(regno < BPF_REG_2 || regno > BPF_REG_5); + + memset(&meta, 0, sizeof(meta)); + + if (may_be_null) { + saved_reg = *mem_reg; + mark_ptr_not_null_reg(mem_reg); } - return check_helper_mem_access(env, regno, mem_size, true, NULL); + err = check_mem_size_reg(env, reg, regno, true, &meta); + /* Check access for BPF_WRITE */ + meta.raw_mode = true; + err = err ?: check_mem_size_reg(env, reg, regno, true, &meta); + + if (may_be_null) + *mem_reg = saved_reg; + return err; } /* Implementation details: @@ -5029,10 +5481,51 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno, return 0; } -static bool arg_type_is_mem_ptr(enum bpf_arg_type type) +static int process_kptr_func(struct bpf_verifier_env *env, int regno, + struct bpf_call_arg_meta *meta) { - return base_type(type) == ARG_PTR_TO_MEM || - base_type(type) == ARG_PTR_TO_UNINIT_MEM; + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; + struct bpf_map_value_off_desc *off_desc; + struct bpf_map *map_ptr = reg->map_ptr; + u32 kptr_off; + int ret; + + if (!tnum_is_const(reg->var_off)) { + verbose(env, + "R%d doesn't have constant offset. kptr has to be at the constant offset\n", + regno); + return -EINVAL; + } + if (!map_ptr->btf) { + verbose(env, "map '%s' has to have BTF in order to use bpf_kptr_xchg\n", + map_ptr->name); + return -EINVAL; + } + if (!map_value_has_kptrs(map_ptr)) { + ret = PTR_ERR_OR_ZERO(map_ptr->kptr_off_tab); + if (ret == -E2BIG) + verbose(env, "map '%s' has more than %d kptr\n", map_ptr->name, + BPF_MAP_VALUE_OFF_MAX); + else if (ret == -EEXIST) + verbose(env, "map '%s' has repeating kptr BTF tags\n", map_ptr->name); + else + verbose(env, "map '%s' has no valid kptr\n", map_ptr->name); + return -EINVAL; + } + + meta->map_ptr = map_ptr; + kptr_off = reg->off + reg->var_off.value; + off_desc = bpf_map_kptr_off_contains(map_ptr, kptr_off); + if (!off_desc) { + verbose(env, "off=%d doesn't point to kptr\n", kptr_off); + return -EACCES; + } + if (off_desc->type != BPF_KPTR_REF) { + verbose(env, "off=%d kptr isn't referenced kptr\n", kptr_off); + return -EACCES; + } + meta->kptr_off_desc = off_desc; + return 0; } static bool arg_type_is_mem_size(enum bpf_arg_type type) @@ -5052,6 +5545,16 @@ static bool arg_type_is_int_ptr(enum bpf_arg_type type) type == ARG_PTR_TO_LONG; } +static bool arg_type_is_release(enum bpf_arg_type type) +{ + return type & OBJ_RELEASE; +} + +static bool arg_type_is_dynptr(enum bpf_arg_type type) +{ + return base_type(type) == ARG_PTR_TO_DYNPTR; +} + static int int_ptr_type_to_size(enum bpf_arg_type type) { if (type == ARG_PTR_TO_INT) @@ -5159,16 +5662,16 @@ static const struct bpf_reg_types alloc_mem_types = { .types = { PTR_TO_MEM | ME static const struct bpf_reg_types const_map_ptr_types = { .types = { CONST_PTR_TO_MAP } }; static const struct bpf_reg_types btf_ptr_types = { .types = { PTR_TO_BTF_ID } }; static const struct bpf_reg_types spin_lock_types = { .types = { PTR_TO_MAP_VALUE } }; -static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_PERCPU_BTF_ID } }; +static const struct bpf_reg_types percpu_btf_ptr_types = { .types = { PTR_TO_BTF_ID | MEM_PERCPU } }; static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } }; static const struct bpf_reg_types stack_ptr_types = { .types = { PTR_TO_STACK } }; static const struct bpf_reg_types const_str_ptr_types = { .types = { PTR_TO_MAP_VALUE } }; static const struct bpf_reg_types timer_types = { .types = { PTR_TO_MAP_VALUE } }; +static const struct bpf_reg_types kptr_types = { .types = { PTR_TO_MAP_VALUE } }; static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_MAP_KEY] = &map_key_value_types, [ARG_PTR_TO_MAP_VALUE] = &map_key_value_types, - [ARG_PTR_TO_UNINIT_MAP_VALUE] = &map_key_value_types, [ARG_CONST_SIZE] = &scalar_types, [ARG_CONST_SIZE_OR_ZERO] = &scalar_types, [ARG_CONST_ALLOC_SIZE_OR_ZERO] = &scalar_types, @@ -5182,7 +5685,6 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_BTF_ID] = &btf_ptr_types, [ARG_PTR_TO_SPIN_LOCK] = &spin_lock_types, [ARG_PTR_TO_MEM] = &mem_types, - [ARG_PTR_TO_UNINIT_MEM] = &mem_types, [ARG_PTR_TO_ALLOC_MEM] = &alloc_mem_types, [ARG_PTR_TO_INT] = &int_ptr_types, [ARG_PTR_TO_LONG] = &int_ptr_types, @@ -5191,11 +5693,14 @@ static const struct bpf_reg_types *compatible_reg_types[__BPF_ARG_TYPE_MAX] = { [ARG_PTR_TO_STACK] = &stack_ptr_types, [ARG_PTR_TO_CONST_STR] = &const_str_ptr_types, [ARG_PTR_TO_TIMER] = &timer_types, + [ARG_PTR_TO_KPTR] = &kptr_types, + [ARG_PTR_TO_DYNPTR] = &stack_ptr_types, }; static int check_reg_type(struct bpf_verifier_env *env, u32 regno, enum bpf_arg_type arg_type, - const u32 *arg_btf_id) + const u32 *arg_btf_id, + struct bpf_call_arg_meta *meta) { struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; enum bpf_reg_type expected, type = reg->type; @@ -5240,6 +5745,13 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno, found: if (reg->type == PTR_TO_BTF_ID) { + /* For bpf_sk_release, it needs to match against first member + * 'struct sock_common', hence make an exception for it. This + * allows bpf_sk_release to work for multiple socket types. + */ + bool strict_type_match = arg_type_is_release(arg_type) && + meta->func_id != BPF_FUNC_sk_release; + if (!arg_btf_id) { if (!compatible->btf_id) { verbose(env, "verifier internal error: missing arg compatible BTF ID\n"); @@ -5248,8 +5760,12 @@ found: arg_btf_id = compatible->btf_id; } - if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, reg->off, - btf_vmlinux, *arg_btf_id)) { + if (meta->func_id == BPF_FUNC_kptr_xchg) { + if (map_kptr_match_type(env, meta->kptr_off_desc, reg, regno)) + return -EACCES; + } else if (!btf_struct_ids_match(&env->log, reg->btf, reg->btf_id, reg->off, + btf_vmlinux, *arg_btf_id, + strict_type_match)) { verbose(env, "R%d is of type %s but %s is expected\n", regno, kernel_type_name(reg->btf, reg->btf_id), kernel_type_name(btf_vmlinux, *arg_btf_id)); @@ -5260,6 +5776,70 @@ found: return 0; } +int check_func_arg_reg_off(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, int regno, + enum bpf_arg_type arg_type) +{ + enum bpf_reg_type type = reg->type; + bool fixed_off_ok = false; + + switch ((u32)type) { + /* Pointer types where reg offset is explicitly allowed: */ + case PTR_TO_STACK: + if (arg_type_is_dynptr(arg_type) && reg->off % BPF_REG_SIZE) { + verbose(env, "cannot pass in dynptr at an offset\n"); + return -EINVAL; + } + fallthrough; + case PTR_TO_PACKET: + case PTR_TO_PACKET_META: + case PTR_TO_MAP_KEY: + case PTR_TO_MAP_VALUE: + case PTR_TO_MEM: + case PTR_TO_MEM | MEM_RDONLY: + case PTR_TO_MEM | MEM_ALLOC: + case PTR_TO_BUF: + case PTR_TO_BUF | MEM_RDONLY: + case SCALAR_VALUE: + /* Some of the argument types nevertheless require a + * zero register offset. + */ + if (base_type(arg_type) != ARG_PTR_TO_ALLOC_MEM) + return 0; + break; + /* All the rest must be rejected, except PTR_TO_BTF_ID which allows + * fixed offset. + */ + case PTR_TO_BTF_ID: + /* When referenced PTR_TO_BTF_ID is passed to release function, + * it's fixed offset must be 0. In the other cases, fixed offset + * can be non-zero. + */ + if (arg_type_is_release(arg_type) && reg->off) { + verbose(env, "R%d must have zero offset when passed to release func\n", + regno); + return -EINVAL; + } + /* For arg is release pointer, fixed_off_ok must be false, but + * we already checked and rejected reg->off != 0 above, so set + * to true to allow fixed offset for all other cases. + */ + fixed_off_ok = true; + break; + default: + break; + } + return __check_ptr_off_reg(env, reg, regno, fixed_off_ok); +} + +static u32 stack_slot_get_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg) +{ + struct bpf_func_state *state = func(env, reg); + int spi = get_spi(reg->off); + + return state->stack[spi].spilled_ptr.id; +} + static int check_func_arg(struct bpf_verifier_env *env, u32 arg, struct bpf_call_arg_meta *meta, const struct bpf_func_proto *fn) @@ -5292,8 +5872,7 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, return -EACCES; } - if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE || - base_type(arg_type) == ARG_PTR_TO_UNINIT_MAP_VALUE) { + if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE) { err = resolve_map_arg_type(env, meta, &arg_type); if (err) return err; @@ -5305,40 +5884,37 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, */ goto skip_type_check; - err = check_reg_type(env, regno, arg_type, fn->arg_btf_id[arg]); + err = check_reg_type(env, regno, arg_type, fn->arg_btf_id[arg], meta); if (err) return err; - switch ((u32)type) { - case SCALAR_VALUE: - /* Pointer types where reg offset is explicitly allowed: */ - case PTR_TO_PACKET: - case PTR_TO_PACKET_META: - case PTR_TO_MAP_KEY: - case PTR_TO_MAP_VALUE: - case PTR_TO_MEM: - case PTR_TO_MEM | MEM_RDONLY: - case PTR_TO_MEM | MEM_ALLOC: - case PTR_TO_BUF: - case PTR_TO_BUF | MEM_RDONLY: - case PTR_TO_STACK: - /* Some of the argument types nevertheless require a - * zero register offset. - */ - if (arg_type == ARG_PTR_TO_ALLOC_MEM) - goto force_off_check; - break; - /* All the rest must be rejected: */ - default: -force_off_check: - err = __check_ptr_off_reg(env, reg, regno, - type == PTR_TO_BTF_ID); - if (err < 0) - return err; - break; - } + err = check_func_arg_reg_off(env, reg, regno, arg_type); + if (err) + return err; skip_type_check: + if (arg_type_is_release(arg_type)) { + if (arg_type_is_dynptr(arg_type)) { + struct bpf_func_state *state = func(env, reg); + int spi = get_spi(reg->off); + + if (!is_spi_bounds_valid(state, spi, BPF_DYNPTR_NR_SLOTS) || + !state->stack[spi].spilled_ptr.id) { + verbose(env, "arg %d is an unacquired reference\n", regno); + return -EINVAL; + } + } else if (!reg->ref_obj_id && !register_is_null(reg)) { + verbose(env, "R%d must be referenced when passed to release function\n", + regno); + return -EINVAL; + } + if (meta->release_regno) { + verbose(env, "verifier internal error: more than one release argument\n"); + return -EFAULT; + } + meta->release_regno = regno; + } + if (reg->ref_obj_id) { if (meta->ref_obj_id) { verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", @@ -5391,8 +5967,7 @@ skip_type_check: err = check_helper_mem_access(env, regno, meta->map_ptr->key_size, false, NULL); - } else if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE || - base_type(arg_type) == ARG_PTR_TO_UNINIT_MAP_VALUE) { + } else if (base_type(arg_type) == ARG_PTR_TO_MAP_VALUE) { if (type_may_be_null(arg_type) && register_is_null(reg)) return 0; @@ -5404,7 +5979,7 @@ skip_type_check: verbose(env, "invalid map_ptr to access map->value\n"); return -EACCES; } - meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MAP_VALUE); + meta->raw_mode = arg_type & MEM_UNINIT; err = check_helper_mem_access(env, regno, meta->map_ptr->value_size, false, meta); @@ -5431,59 +6006,49 @@ skip_type_check: return -EACCES; } else if (arg_type == ARG_PTR_TO_FUNC) { meta->subprogno = reg->subprogno; - } else if (arg_type_is_mem_ptr(arg_type)) { + } else if (base_type(arg_type) == ARG_PTR_TO_MEM) { /* The access to this pointer is only checked when we hit the * next is_mem_size argument below. */ - meta->raw_mode = (arg_type == ARG_PTR_TO_UNINIT_MEM); + meta->raw_mode = arg_type & MEM_UNINIT; } else if (arg_type_is_mem_size(arg_type)) { bool zero_size_allowed = (arg_type == ARG_CONST_SIZE_OR_ZERO); - /* This is used to refine r0 return value bounds for helpers - * that enforce this value as an upper bound on return values. - * See do_refine_retval_range() for helpers that can refine - * the return value. C type of helper is u32 so we pull register - * bound from umax_value however, if negative verifier errors - * out. Only upper bounds can be learned because retval is an - * int type and negative retvals are allowed. - */ - meta->msize_max_value = reg->umax_value; + err = check_mem_size_reg(env, reg, regno, zero_size_allowed, meta); + } else if (arg_type_is_dynptr(arg_type)) { + if (arg_type & MEM_UNINIT) { + if (!is_dynptr_reg_valid_uninit(env, reg)) { + verbose(env, "Dynptr has to be an uninitialized dynptr\n"); + return -EINVAL; + } - /* The register is SCALAR_VALUE; the access check - * happens using its boundaries. - */ - if (!tnum_is_const(reg->var_off)) - /* For unprivileged variable accesses, disable raw - * mode so that the program is required to - * initialize all the memory that the helper could - * just partially fill up. + /* We only support one dynptr being uninitialized at the moment, + * which is sufficient for the helper functions we have right now. */ - meta = NULL; + if (meta->uninit_dynptr_regno) { + verbose(env, "verifier internal error: multiple uninitialized dynptr args\n"); + return -EFAULT; + } - if (reg->smin_value < 0) { - verbose(env, "R%d min value is negative, either use unsigned or 'var &= const'\n", - regno); - return -EACCES; - } + meta->uninit_dynptr_regno = regno; + } else if (!is_dynptr_reg_valid_init(env, reg, arg_type)) { + const char *err_extra = ""; - if (reg->umin_value == 0) { - err = check_helper_mem_access(env, regno - 1, 0, - zero_size_allowed, - meta); - if (err) - return err; - } + switch (arg_type & DYNPTR_TYPE_FLAG_MASK) { + case DYNPTR_TYPE_LOCAL: + err_extra = "local "; + break; + case DYNPTR_TYPE_RINGBUF: + err_extra = "ringbuf "; + break; + default: + break; + } - if (reg->umax_value >= BPF_MAX_VAR_SIZ) { - verbose(env, "R%d unbounded memory access, use 'var &= const' or 'if (var < const)'\n", - regno); - return -EACCES; + verbose(env, "Expected an initialized %sdynptr as arg #%d\n", + err_extra, arg + 1); + return -EINVAL; } - err = check_helper_mem_access(env, regno - 1, - reg->umax_value, - zero_size_allowed, meta); - if (!err) - err = mark_chain_precision(env, regno); } else if (arg_type_is_alloc_size(arg_type)) { if (!tnum_is_const(reg->var_off)) { verbose(env, "R%d is not a known constant'\n", @@ -5520,7 +6085,8 @@ skip_type_check: } err = check_map_access(env, regno, reg->off, - map->value_size - reg->off, false); + map->value_size - reg->off, false, + ACCESS_HELPER); if (err) return err; @@ -5536,6 +6102,9 @@ skip_type_check: verbose(env, "string is not zero-terminated\n"); return -EINVAL; } + } else if (arg_type == ARG_PTR_TO_KPTR) { + if (process_kptr_func(env, regno, meta)) + return -EACCES; } return err; @@ -5601,7 +6170,10 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_MAP_TYPE_RINGBUF: if (func_id != BPF_FUNC_ringbuf_output && func_id != BPF_FUNC_ringbuf_reserve && - func_id != BPF_FUNC_ringbuf_query) + func_id != BPF_FUNC_ringbuf_query && + func_id != BPF_FUNC_ringbuf_reserve_dynptr && + func_id != BPF_FUNC_ringbuf_submit_dynptr && + func_id != BPF_FUNC_ringbuf_discard_dynptr) goto error; break; case BPF_MAP_TYPE_STACK_TRACE: @@ -5717,6 +6289,9 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, case BPF_FUNC_ringbuf_output: case BPF_FUNC_ringbuf_reserve: case BPF_FUNC_ringbuf_query: + case BPF_FUNC_ringbuf_reserve_dynptr: + case BPF_FUNC_ringbuf_submit_dynptr: + case BPF_FUNC_ringbuf_discard_dynptr: if (map->map_type != BPF_MAP_TYPE_RINGBUF) goto error; break; @@ -5771,6 +6346,12 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, map->map_type != BPF_MAP_TYPE_BLOOM_FILTER) goto error; break; + case BPF_FUNC_map_lookup_percpu_elem: + if (map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY && + map->map_type != BPF_MAP_TYPE_PERCPU_HASH && + map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH) + goto error; + break; case BPF_FUNC_sk_storage_get: case BPF_FUNC_sk_storage_delete: if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) @@ -5822,10 +6403,8 @@ static bool check_raw_mode_ok(const struct bpf_func_proto *fn) static bool check_args_pair_invalid(enum bpf_arg_type arg_curr, enum bpf_arg_type arg_next) { - return (arg_type_is_mem_ptr(arg_curr) && - !arg_type_is_mem_size(arg_next)) || - (!arg_type_is_mem_ptr(arg_curr) && - arg_type_is_mem_size(arg_next)); + return (base_type(arg_curr) == ARG_PTR_TO_MEM) != + arg_type_is_mem_size(arg_next); } static bool check_arg_pair_ok(const struct bpf_func_proto *fn) @@ -5836,7 +6415,7 @@ static bool check_arg_pair_ok(const struct bpf_func_proto *fn) * helper function specification. */ if (arg_type_is_mem_size(fn->arg1_type) || - arg_type_is_mem_ptr(fn->arg5_type) || + base_type(fn->arg5_type) == ARG_PTR_TO_MEM || check_args_pair_invalid(fn->arg1_type, fn->arg2_type) || check_args_pair_invalid(fn->arg2_type, fn->arg3_type) || check_args_pair_invalid(fn->arg3_type, fn->arg4_type) || @@ -5878,17 +6457,18 @@ static bool check_btf_id_ok(const struct bpf_func_proto *fn) int i; for (i = 0; i < ARRAY_SIZE(fn->arg_type); i++) { - if (fn->arg_type[i] == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i]) + if (base_type(fn->arg_type[i]) == ARG_PTR_TO_BTF_ID && !fn->arg_btf_id[i]) return false; - if (fn->arg_type[i] != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i]) + if (base_type(fn->arg_type[i]) != ARG_PTR_TO_BTF_ID && fn->arg_btf_id[i]) return false; } return true; } -static int check_func_proto(const struct bpf_func_proto *fn, int func_id) +static int check_func_proto(const struct bpf_func_proto *fn, int func_id, + struct bpf_call_arg_meta *meta) { return check_raw_mode_ok(fn) && check_arg_pair_ok(fn) && @@ -6383,7 +6963,8 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta, func_id != BPF_FUNC_map_pop_elem && func_id != BPF_FUNC_map_peek_elem && func_id != BPF_FUNC_for_each_map_elem && - func_id != BPF_FUNC_redirect_map) + func_id != BPF_FUNC_redirect_map && + func_id != BPF_FUNC_map_lookup_percpu_elem) return 0; if (map == NULL) { @@ -6572,7 +7153,7 @@ 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, func_id); + err = check_func_proto(fn, func_id, &meta); if (err) { verbose(env, "kernel subsystem misconfigured func %s#%d\n", func_id_name(func_id), func_id); @@ -6605,8 +7186,35 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn return err; } - if (is_release_function(func_id)) { - err = release_reference(env, meta.ref_obj_id); + regs = cur_regs(env); + + if (meta.uninit_dynptr_regno) { + /* we write BPF_DW bits (8 bytes) at a time */ + for (i = 0; i < BPF_DYNPTR_SIZE; i += 8) { + err = check_mem_access(env, insn_idx, meta.uninit_dynptr_regno, + i, BPF_DW, BPF_WRITE, -1, false); + if (err) + return err; + } + + err = mark_stack_slots_dynptr(env, ®s[meta.uninit_dynptr_regno], + fn->arg_type[meta.uninit_dynptr_regno - BPF_REG_1], + insn_idx); + if (err) + return err; + } + + 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 (meta.ref_obj_id) + err = release_reference(env, meta.ref_obj_id); + /* meta.ref_obj_id can only be 0 if register that is meant to be + * released is NULL, which must be > R0. + */ + else if (register_is_null(®s[meta.release_regno])) + err = 0; if (err) { verbose(env, "func %s#%d reference has not been acquired before\n", func_id_name(func_id), func_id); @@ -6614,8 +7222,6 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn } } - regs = cur_regs(env); - switch (func_id) { case BPF_FUNC_tail_call: err = check_reference_leak(env); @@ -6652,6 +7258,12 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn err = __check_func_call(env, insn, insn_idx_p, meta.subprogno, set_loop_callback_state); break; + case BPF_FUNC_dynptr_from_mem: + if (regs[BPF_REG_1].type != PTR_TO_MAP_VALUE) { + verbose(env, "Unsupported reg type %s for bpf_dynptr_from_mem data\n", + reg_type_str(env, regs[BPF_REG_1].type)); + return -EACCES; + } } if (err) @@ -6739,21 +7351,25 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn regs[BPF_REG_0].btf_id = meta.ret_btf_id; } } else if (base_type(ret_type) == RET_PTR_TO_BTF_ID) { + struct btf *ret_btf; int ret_btf_id; mark_reg_known_zero(env, regs, BPF_REG_0); regs[BPF_REG_0].type = PTR_TO_BTF_ID | ret_flag; - ret_btf_id = *fn->ret_btf_id; + if (func_id == BPF_FUNC_kptr_xchg) { + ret_btf = meta.kptr_off_desc->kptr.btf; + ret_btf_id = meta.kptr_off_desc->kptr.btf_id; + } else { + ret_btf = btf_vmlinux; + ret_btf_id = *fn->ret_btf_id; + } if (ret_btf_id == 0) { verbose(env, "invalid return type %u of func %s#%d\n", base_type(ret_type), func_id_name(func_id), func_id); return -EINVAL; } - /* current BPF helper definitions are only coming from - * built-in code with type IDs from vmlinux BTF - */ - regs[BPF_REG_0].btf = btf_vmlinux; + regs[BPF_REG_0].btf = ret_btf; regs[BPF_REG_0].btf_id = ret_btf_id; } else { verbose(env, "unknown return type %u of func %s#%d\n", @@ -6776,6 +7392,21 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn regs[BPF_REG_0].id = id; /* For release_reference() */ regs[BPF_REG_0].ref_obj_id = id; + } else if (func_id == BPF_FUNC_dynptr_data) { + int dynptr_id = 0, i; + + /* Find the id of the dynptr we're acquiring a reference to */ + for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { + if (arg_type_is_dynptr(fn->arg_type[i])) { + if (dynptr_id) { + verbose(env, "verifier internal error: multiple dynptr args in func\n"); + return -EFAULT; + } + dynptr_id = stack_slot_get_id(env, ®s[BPF_REG_1 + i]); + } + } + /* For release_reference() */ + regs[BPF_REG_0].ref_obj_id = dynptr_id; } do_refine_retval_range(regs, fn->ret_type, func_id, &meta); @@ -6842,22 +7473,23 @@ static void mark_btf_func_reg_size(struct bpf_verifier_env *env, u32 regno, } } -static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn) +static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, + int *insn_idx_p) { const struct btf_type *t, *func, *func_proto, *ptr_type; struct bpf_reg_state *regs = cur_regs(env); const char *func_name, *ptr_type_name; u32 i, nargs, func_id, ptr_type_id; - struct module *btf_mod = NULL; + int err, insn_idx = *insn_idx_p; const struct btf_param *args; struct btf *desc_btf; - int err; + bool acq; /* skip for now, but return error when we find this in fixup_kfunc_call */ if (!insn->imm) return 0; - desc_btf = find_kfunc_desc_btf(env, insn->imm, insn->off, &btf_mod); + desc_btf = find_kfunc_desc_btf(env, insn->off); if (IS_ERR(desc_btf)) return PTR_ERR(desc_btf); @@ -6866,23 +7498,43 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn) func_name = btf_name_by_offset(desc_btf, func->name_off); func_proto = btf_type_by_id(desc_btf, func->type); - if (!env->ops->check_kfunc_call || - !env->ops->check_kfunc_call(func_id, btf_mod)) { + if (!btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_CHECK, func_id)) { verbose(env, "calling kernel function %s is not allowed\n", func_name); return -EACCES; } + acq = btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_ACQUIRE, func_id); + /* Check the arguments */ err = btf_check_kfunc_arg_match(env, desc_btf, func_id, regs); - if (err) + if (err < 0) return err; + /* In case of release function, we get register number of refcounted + * PTR_TO_BTF_ID back from btf_check_kfunc_arg_match, do the release now + */ + if (err) { + err = release_reference(env, regs[err].ref_obj_id); + if (err) { + verbose(env, "kfunc %s#%d reference has not been acquired before\n", + func_name, func_id); + return err; + } + } for (i = 0; i < CALLER_SAVED_REGS; i++) mark_reg_not_init(env, regs, caller_saved[i]); /* Check return type */ t = btf_type_skip_modifiers(desc_btf, func_proto->type, NULL); + + if (acq && !btf_type_is_ptr(t)) { + verbose(env, "acquire kernel function does not return PTR_TO_BTF_ID\n"); + return -EINVAL; + } + if (btf_type_is_scalar(t)) { mark_reg_unknown(env, regs, BPF_REG_0); mark_btf_func_reg_size(env, BPF_REG_0, t->size); @@ -6901,7 +7553,21 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn) regs[BPF_REG_0].btf = desc_btf; regs[BPF_REG_0].type = PTR_TO_BTF_ID; regs[BPF_REG_0].btf_id = ptr_type_id; + if (btf_kfunc_id_set_contains(desc_btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_RET_NULL, func_id)) { + regs[BPF_REG_0].type |= PTR_MAYBE_NULL; + /* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */ + regs[BPF_REG_0].id = ++env->id_gen; + } mark_btf_func_reg_size(env, BPF_REG_0, sizeof(void *)); + if (acq) { + int id = acquire_reference_state(env, insn_idx); + + if (id < 0) + return id; + regs[BPF_REG_0].id = id; + regs[BPF_REG_0].ref_obj_id = id; + } } /* else { add_kfunc_call() ensures it is btf_type_is_void(t) } */ nargs = btf_type_vlen(func_proto); @@ -7305,7 +7971,7 @@ static int sanitize_check_bounds(struct bpf_verifier_env *env, return -EACCES; break; case PTR_TO_MAP_VALUE: - if (check_map_access(env, dst, dst_reg->off, 1, false)) { + if (check_map_access(env, dst, dst_reg->off, 1, false, ACCESS_HELPER)) { verbose(env, "R%d pointer arithmetic of map value goes out of range, " "prohibited for !root\n", dst); return -EACCES; @@ -9548,7 +10214,6 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) dst_reg->mem_size = aux->btf_var.mem_size; break; case PTR_TO_BTF_ID: - case PTR_TO_PERCPU_BTF_ID: dst_reg->btf = aux->btf_var.btf; dst_reg->btf_id = aux->btf_var.btf_id; break; @@ -10273,8 +10938,7 @@ static void adjust_btf_func(struct bpf_verifier_env *env) aux->func_info[i].insn_off = env->subprog_info[i].start; } -#define MIN_BPF_LINEINFO_SIZE (offsetof(struct bpf_line_info, line_col) + \ - sizeof(((struct bpf_line_info *)(0))->line_col)) +#define MIN_BPF_LINEINFO_SIZE offsetofend(struct bpf_line_info, line_col) #define MAX_LINEINFO_REC_SIZE MAX_FUNCINFO_REC_SIZE static int check_btf_line(struct bpf_verifier_env *env, @@ -11549,7 +12213,7 @@ static int do_check(struct bpf_verifier_env *env) if (insn->src_reg == BPF_PSEUDO_CALL) err = check_func_call(env, insn, &env->insn_idx); else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) - err = check_kfunc_call(env, insn); + err = check_kfunc_call(env, insn, &env->insn_idx); else err = check_helper_call(env, insn, &env->insn_idx); if (err) @@ -11748,7 +12412,7 @@ static int check_pseudo_btf_id(struct bpf_verifier_env *env, type = t->type; t = btf_type_skip_modifiers(btf, type, NULL); if (percpu) { - aux->btf_var.reg_type = PTR_TO_PERCPU_BTF_ID; + aux->btf_var.reg_type = PTR_TO_BTF_ID | MEM_PERCPU; aux->btf_var.btf = btf; aux->btf_var.btf_id = type; } else if (!btf_type_is_struct(t)) { @@ -12696,7 +13360,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) if (!ctx_access) continue; - switch (env->insn_aux_data[i + delta].ptr_type) { + switch ((int)env->insn_aux_data[i + delta].ptr_type) { case PTR_TO_CTX: if (!ops->convert_ctx_access) continue; @@ -12713,6 +13377,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) convert_ctx_access = bpf_xdp_sock_convert_ctx_access; break; case PTR_TO_BTF_ID: + case PTR_TO_BTF_ID | PTR_UNTRUSTED: if (type == BPF_READ) { insn->code = BPF_LDX | BPF_PROBE_MEM | BPF_SIZE((insn)->code); @@ -12897,6 +13562,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) func[i]->aux->name[0] = 'F'; func[i]->aux->stack_depth = env->subprog_info[i].stack_depth; func[i]->jit_requested = 1; + func[i]->blinding_requested = prog->blinding_requested; func[i]->aux->kfunc_tab = prog->aux->kfunc_tab; func[i]->aux->kfunc_btf_tab = prog->aux->kfunc_btf_tab; func[i]->aux->linfo = prog->aux->linfo; @@ -12992,6 +13658,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) prog->jited = 1; prog->bpf_func = func[0]->bpf_func; + prog->jited_len = func[0]->jited_len; prog->aux->func = func; prog->aux->func_cnt = env->subprog_cnt; bpf_prog_jit_attempt_done(prog); @@ -13019,6 +13686,7 @@ out_free: out_undo_insn: /* cleanup main prog to be interpreted */ prog->jit_requested = 0; + prog->blinding_requested = 0; for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { if (!bpf_pseudo_call(insn)) continue; @@ -13112,7 +13780,6 @@ static int do_misc_fixups(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; enum bpf_attach_type eatype = prog->expected_attach_type; - bool expect_blinding = bpf_jit_blinding_enabled(prog); enum bpf_prog_type prog_type = resolve_prog_type(prog); struct bpf_insn *insn = prog->insnsi; const struct bpf_func_proto *fn; @@ -13276,7 +13943,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) insn->code = BPF_JMP | BPF_TAIL_CALL; aux = &env->insn_aux_data[i + delta]; - if (env->bpf_capable && !expect_blinding && + if (env->bpf_capable && !prog->blinding_requested && prog->jit_requested && !bpf_map_key_poisoned(aux) && !bpf_map_ptr_poisoned(aux) && @@ -13364,6 +14031,26 @@ static int do_misc_fixups(struct bpf_verifier_env *env) goto patch_call_imm; } + if (insn->imm == BPF_FUNC_task_storage_get || + insn->imm == BPF_FUNC_sk_storage_get || + insn->imm == BPF_FUNC_inode_storage_get) { + if (env->prog->aux->sleepable) + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_KERNEL); + else + insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_ATOMIC); + insn_buf[1] = *insn; + cnt = 2; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + goto patch_call_imm; + } + /* BPF_EMIT_CALL() assumptions in some of the map_gen_lookup * and other inlining handlers are currently limited to 64 bit * only. @@ -13376,7 +14063,8 @@ static int do_misc_fixups(struct bpf_verifier_env *env) insn->imm == BPF_FUNC_map_pop_elem || insn->imm == BPF_FUNC_map_peek_elem || insn->imm == BPF_FUNC_redirect_map || - insn->imm == BPF_FUNC_for_each_map_elem)) { + insn->imm == BPF_FUNC_for_each_map_elem || + insn->imm == BPF_FUNC_map_lookup_percpu_elem)) { aux = &env->insn_aux_data[i + delta]; if (bpf_map_ptr_poisoned(aux)) goto patch_call_imm; @@ -13425,6 +14113,8 @@ static int do_misc_fixups(struct bpf_verifier_env *env) bpf_callback_t callback_fn, void *callback_ctx, u64 flags))NULL)); + BUILD_BUG_ON(!__same_type(ops->map_lookup_percpu_elem, + (void *(*)(struct bpf_map *map, void *key, u32 cpu))NULL)); patch_map_ops_generic: switch (insn->imm) { @@ -13452,6 +14142,9 @@ patch_map_ops_generic: case BPF_FUNC_for_each_map_elem: insn->imm = BPF_CALL_IMM(ops->map_for_each_callback); continue; + case BPF_FUNC_map_lookup_percpu_elem: + insn->imm = BPF_CALL_IMM(ops->map_lookup_percpu_elem); + continue; } goto patch_call_imm; |