@@ -311,7 +311,9 @@ enum bpf_type_flag {
/* PTR may be NULL. */
PTR_MAYBE_NULL = BIT(0 + BPF_BASE_TYPE_BITS),
- /* MEM is read-only. */
+ /* MEM is read-only. When applied on bpf_arg, it indicates the arg is
+ * compatible with both mutable and immutable memory.
+ */
MEM_RDONLY = BIT(1 + BPF_BASE_TYPE_BITS),
__BPF_TYPE_LAST_FLAG = MEM_RDONLY,
@@ -6353,7 +6353,7 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
.func = bpf_btf_find_by_name_kind,
.gpl_only = false,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_ANYTHING,
@@ -1789,7 +1789,7 @@ static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
@@ -531,7 +531,7 @@ const struct bpf_func_proto bpf_strtol_proto = {
.func = bpf_strtol,
.gpl_only = false,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_LONG,
@@ -559,7 +559,7 @@ const struct bpf_func_proto bpf_strtoul_proto = {
.func = bpf_strtoul,
.gpl_only = false,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_LONG,
@@ -645,7 +645,7 @@ const struct bpf_func_proto bpf_event_output_data_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -1026,7 +1026,7 @@ const struct bpf_func_proto bpf_snprintf_proto = {
.arg1_type = ARG_PTR_TO_MEM_OR_NULL,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_PTR_TO_CONST_STR,
- .arg4_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -444,7 +444,7 @@ const struct bpf_func_proto bpf_ringbuf_output_proto = {
.func = bpf_ringbuf_output,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
@@ -4773,7 +4773,7 @@ static const struct bpf_func_proto bpf_sys_bpf_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
@@ -5048,7 +5048,6 @@ static const struct bpf_reg_types mem_types = {
PTR_TO_MAP_VALUE,
PTR_TO_MEM,
PTR_TO_BUF,
- PTR_TO_BUF | MEM_RDONLY,
},
};
@@ -5118,6 +5117,21 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
return -EFAULT;
}
+ /* ARG_PTR_TO_MEM + RDONLY is compatible with PTR_TO_MEM and PTR_TO_MEM + RDONLY,
+ * but ARG_PTR_TO_MEM is compatible only with PTR_TO_MEM and NOT with PTR_TO_MEM + RDONLY
+ *
+ * Same for MAYBE_NULL:
+ *
+ * ARG_PTR_TO_MEM + MAYBE_NULL is compatible with PTR_TO_MEM and PTR_TO_MEM + MAYBE_NULL,
+ * but ARG_PTR_TO_MEM is compatible only with PTR_TO_MEM but NOT with PTR_TO_MEM + MAYBE_NULL
+ *
+ * Therefore we fold these flags depending on the arg_type before comparison.
+ */
+ if (arg_type & MEM_RDONLY)
+ type &= ~MEM_RDONLY;
+ if (arg_type & PTR_MAYBE_NULL)
+ type &= ~PTR_MAYBE_NULL;
+
for (i = 0; i < ARRAY_SIZE(compatible->types); i++) {
expected = compatible->types[i];
if (expected == NOT_INIT)
@@ -5127,14 +5141,14 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno,
goto found;
}
- verbose(env, "R%d type=%s expected=", regno, reg_type_str(env, type));
+ verbose(env, "R%d type=%s expected=", regno, reg_type_str(env, reg->type));
for (j = 0; j + 1 < i; j++)
verbose(env, "%s, ", reg_type_str(env, compatible->types[j]));
verbose(env, "%s\n", reg_type_str(env, compatible->types[j]));
return -EACCES;
found:
- if (type == PTR_TO_BTF_ID) {
+ if (reg->type == PTR_TO_BTF_ID) {
if (!arg_btf_id) {
if (!compatible->btf_id) {
verbose(env, "verifier internal error: missing arg compatible BTF ID\n");
@@ -345,7 +345,7 @@ static const struct bpf_func_proto bpf_probe_write_user_proto = {
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
@@ -394,7 +394,7 @@ static const struct bpf_func_proto bpf_trace_printk_proto = {
.func = bpf_trace_printk,
.gpl_only = true,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
};
@@ -450,9 +450,9 @@ static const struct bpf_func_proto bpf_trace_vprintk_proto = {
.func = bpf_trace_vprintk,
.gpl_only = true,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM,
+ .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
- .arg3_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -492,9 +492,9 @@ static const struct bpf_func_proto bpf_seq_printf_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
- .arg4_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -509,7 +509,7 @@ static const struct bpf_func_proto bpf_seq_write_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -533,7 +533,7 @@ static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
@@ -694,7 +694,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -1004,7 +1004,7 @@ const struct bpf_func_proto bpf_snprintf_btf_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM,
.arg2_type = ARG_CONST_SIZE,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE,
.arg5_type = ARG_ANYTHING,
};
@@ -1334,7 +1334,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -1556,7 +1556,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -1610,7 +1610,7 @@ static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
@@ -1712,7 +1712,7 @@ static const struct bpf_func_proto bpf_skb_store_bytes_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE,
.arg5_type = ARG_ANYTHING,
};
@@ -2017,9 +2017,9 @@ static const struct bpf_func_proto bpf_csum_diff_proto = {
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg1_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
- .arg3_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
.arg5_type = ARG_ANYTHING,
};
@@ -2540,7 +2540,7 @@ static const struct bpf_func_proto bpf_redirect_neigh_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
- .arg2_type = ARG_PTR_TO_MEM_OR_NULL,
+ .arg2_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
@@ -4173,7 +4173,7 @@ static const struct bpf_func_proto bpf_skb_event_output_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -4187,7 +4187,7 @@ const struct bpf_func_proto bpf_skb_output_proto = {
.arg1_btf_id = &bpf_skb_output_btf_ids[0],
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -4370,7 +4370,7 @@ static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
};
@@ -4396,7 +4396,7 @@ static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
@@ -4566,7 +4566,7 @@ static const struct bpf_func_proto bpf_xdp_event_output_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -4580,7 +4580,7 @@ const struct bpf_func_proto bpf_xdp_output_proto = {
.arg1_btf_id = &bpf_xdp_output_btf_ids[0],
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
@@ -5066,7 +5066,7 @@ const struct bpf_func_proto bpf_sk_setsockopt_proto = {
.arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE,
};
@@ -5100,7 +5100,7 @@ static const struct bpf_func_proto bpf_sock_addr_setsockopt_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE,
};
@@ -5134,7 +5134,7 @@ static const struct bpf_func_proto bpf_sock_ops_setsockopt_proto = {
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE,
};
@@ -5309,7 +5309,7 @@ static const struct bpf_func_proto bpf_bind_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
@@ -5897,7 +5897,7 @@ static const struct bpf_func_proto bpf_lwt_in_push_encap_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE
};
@@ -5907,7 +5907,7 @@ static const struct bpf_func_proto bpf_lwt_xmit_push_encap_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE
};
@@ -5950,7 +5950,7 @@ static const struct bpf_func_proto bpf_lwt_seg6_store_bytes_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE
};
@@ -6038,7 +6038,7 @@ static const struct bpf_func_proto bpf_lwt_seg6_action_proto = {
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
- .arg3_type = ARG_PTR_TO_MEM,
+ .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE
};
@@ -6263,7 +6263,7 @@ static const struct bpf_func_proto bpf_skc_lookup_tcp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6282,7 +6282,7 @@ static const struct bpf_func_proto bpf_sk_lookup_tcp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6301,7 +6301,7 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6338,7 +6338,7 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_udp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6361,7 +6361,7 @@ static const struct bpf_func_proto bpf_xdp_skc_lookup_tcp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6384,7 +6384,7 @@ static const struct bpf_func_proto bpf_xdp_sk_lookup_tcp_proto = {
.pkt_access = true,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6403,7 +6403,7 @@ static const struct bpf_func_proto bpf_sock_addr_skc_lookup_tcp_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_SOCK_COMMON_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6422,7 +6422,7 @@ static const struct bpf_func_proto bpf_sock_addr_sk_lookup_tcp_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6441,7 +6441,7 @@ static const struct bpf_func_proto bpf_sock_addr_sk_lookup_udp_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
.arg5_type = ARG_ANYTHING,
@@ -6754,9 +6754,9 @@ static const struct bpf_func_proto bpf_tcp_check_syncookie_proto = {
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE,
};
@@ -6823,9 +6823,9 @@ static const struct bpf_func_proto bpf_tcp_gen_syncookie_proto = {
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
- .arg4_type = ARG_PTR_TO_MEM,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg5_type = ARG_CONST_SIZE,
};
@@ -7054,7 +7054,7 @@ static const struct bpf_func_proto bpf_sock_ops_store_hdr_opt_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
};
Some helper functions may modify its arguments, for example, bpf_d_path, bpf_get_stack etc. Previously, their argument types were marked as ARG_PTR_TO_MEM, which is compatible with read-only mem types, such as PTR_TO_RDONLY_BUF. Therefore it's legitimate to modify a read-only memory by passing it into one of such helper functions. This patch tags the bpf_args compatible with immutable memory with MEM_RDONLY flag. The arguments that don't have this flag will be only compatible with mutable memory types, preventing the helper from modifying a read-only memory. The bpf_args that have MEM_RDONLY are compatible with both mutable memory and immutable memory. Signed-off-by: Hao Luo <haoluo@google.com> --- include/linux/bpf.h | 4 ++- kernel/bpf/btf.c | 2 +- kernel/bpf/cgroup.c | 2 +- kernel/bpf/helpers.c | 8 ++--- kernel/bpf/ringbuf.c | 2 +- kernel/bpf/syscall.c | 2 +- kernel/bpf/verifier.c | 20 +++++++++++-- kernel/trace/bpf_trace.c | 26 ++++++++-------- net/core/filter.c | 64 ++++++++++++++++++++-------------------- 9 files changed, 73 insertions(+), 57 deletions(-)