diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 91 |
1 files changed, 85 insertions, 6 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9a6703bc3f36..8d6979db48d8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -409,7 +409,9 @@ static bool reg_type_may_be_null(enum bpf_reg_type type) type == PTR_TO_SOCK_COMMON_OR_NULL || type == PTR_TO_TCP_SOCK_OR_NULL || type == PTR_TO_BTF_ID_OR_NULL || - type == PTR_TO_MEM_OR_NULL; + type == PTR_TO_MEM_OR_NULL || + type == PTR_TO_RDONLY_BUF_OR_NULL || + type == PTR_TO_RDWR_BUF_OR_NULL; } static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg) @@ -503,6 +505,10 @@ static const char * const reg_type_str[] = { [PTR_TO_BTF_ID_OR_NULL] = "ptr_or_null_", [PTR_TO_MEM] = "mem", [PTR_TO_MEM_OR_NULL] = "mem_or_null", + [PTR_TO_RDONLY_BUF] = "rdonly_buf", + [PTR_TO_RDONLY_BUF_OR_NULL] = "rdonly_buf_or_null", + [PTR_TO_RDWR_BUF] = "rdwr_buf", + [PTR_TO_RDWR_BUF_OR_NULL] = "rdwr_buf_or_null", }; static char slot_type_char[] = { @@ -2173,6 +2179,10 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case PTR_TO_XDP_SOCK: case PTR_TO_BTF_ID: case PTR_TO_BTF_ID_OR_NULL: + case PTR_TO_RDONLY_BUF: + case PTR_TO_RDONLY_BUF_OR_NULL: + case PTR_TO_RDWR_BUF: + case PTR_TO_RDWR_BUF_OR_NULL: return true; default: return false; @@ -3052,14 +3062,15 @@ int check_ctx_reg(struct bpf_verifier_env *env, return 0; } -static int check_tp_buffer_access(struct bpf_verifier_env *env, - const struct bpf_reg_state *reg, - int regno, int off, int size) +static int __check_buffer_access(struct bpf_verifier_env *env, + const char *buf_info, + const struct bpf_reg_state *reg, + int regno, int off, int size) { if (off < 0) { verbose(env, - "R%d invalid tracepoint buffer access: off=%d, size=%d", - regno, off, size); + "R%d invalid %s buffer access: off=%d, size=%d", + regno, buf_info, off, size); return -EACCES; } if (!tnum_is_const(reg->var_off) || reg->var_off.value) { @@ -3071,12 +3082,45 @@ static int check_tp_buffer_access(struct bpf_verifier_env *env, regno, off, tn_buf); return -EACCES; } + + return 0; +} + +static int check_tp_buffer_access(struct bpf_verifier_env *env, + const struct bpf_reg_state *reg, + int regno, int off, int size) +{ + int err; + + err = __check_buffer_access(env, "tracepoint", reg, regno, off, size); + if (err) + return err; + if (off + size > env->prog->aux->max_tp_access) env->prog->aux->max_tp_access = off + size; return 0; } +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) +{ + int err; + + err = __check_buffer_access(env, buf_info, reg, regno, off, size); + if (err) + return err; + + if (off + size > *max_access) + *max_access = off + size; + + return 0; +} + /* BPF architecture zero extends alu32 ops into 64-bit registesr */ static void zext_32_to_64(struct bpf_reg_state *reg) { @@ -3427,6 +3471,23 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn } else if (reg->type == CONST_PTR_TO_MAP) { err = check_ptr_to_map_access(env, regs, regno, off, size, t, value_regno); + } else if (reg->type == PTR_TO_RDONLY_BUF) { + if (t == BPF_WRITE) { + verbose(env, "R%d cannot write into %s\n", + regno, reg_type_str[reg->type]); + return -EACCES; + } + err = check_buffer_access(env, reg, regno, off, size, "rdonly", + false, + &env->prog->aux->max_rdonly_access); + if (!err && value_regno >= 0) + mark_reg_unknown(env, regs, value_regno); + } else if (reg->type == PTR_TO_RDWR_BUF) { + err = check_buffer_access(env, reg, regno, off, size, "rdwr", + false, + &env->prog->aux->max_rdwr_access); + if (!err && t == BPF_READ && value_regno >= 0) + mark_reg_unknown(env, regs, value_regno); } else { verbose(env, "R%d invalid mem access '%s'\n", regno, reg_type_str[reg->type]); @@ -3668,6 +3729,18 @@ static int check_helper_mem_access(struct bpf_verifier_env *env, int regno, return check_mem_region_access(env, regno, reg->off, access_size, reg->mem_size, zero_size_allowed); + case PTR_TO_RDONLY_BUF: + if (meta && meta->raw_mode) + return -EACCES; + return check_buffer_access(env, reg, regno, reg->off, + access_size, zero_size_allowed, + "rdonly", + &env->prog->aux->max_rdonly_access); + case PTR_TO_RDWR_BUF: + return check_buffer_access(env, reg, regno, reg->off, + access_size, zero_size_allowed, + "rdwr", + &env->prog->aux->max_rdwr_access); default: /* scalar_value|ptr_to_stack or invalid ptr */ return check_stack_boundary(env, regno, access_size, zero_size_allowed, meta); @@ -3933,6 +4006,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, else if (!type_is_pkt_pointer(type) && type != PTR_TO_MAP_VALUE && type != PTR_TO_MEM && + type != PTR_TO_RDONLY_BUF && + type != PTR_TO_RDWR_BUF && type != expected_type) goto err_type; meta->raw_mode = arg_type == ARG_PTR_TO_UNINIT_MEM; @@ -6806,6 +6881,10 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, reg->type = PTR_TO_BTF_ID; } else if (reg->type == PTR_TO_MEM_OR_NULL) { reg->type = PTR_TO_MEM; + } else if (reg->type == PTR_TO_RDONLY_BUF_OR_NULL) { + reg->type = PTR_TO_RDONLY_BUF; + } else if (reg->type == PTR_TO_RDWR_BUF_OR_NULL) { + reg->type = PTR_TO_RDWR_BUF; } if (is_null) { /* We don't need id and ref_obj_id from this point |