diff --git a/src/encrypt.c b/src/encrypt.c
index cc9bd8a8..d204f104 100644
--- a/src/encrypt.c
+++ b/src/encrypt.c
@@ -726,7 +726,8 @@ cipher_context_init(cipher_ctx_t *ctx, int method, int enc)
         FATAL("Cannot initialize PolarSSL cipher context");
     }
 #elif defined(USE_CRYPTO_MBEDTLS)
-    ctx->evp = (cipher_evp_t *)ss_malloc(sizeof(cipher_evp_t));
+    ctx->evp = ss_malloc(sizeof(cipher_evp_t));
+    memset(ctx->evp, 0, sizeof(cipher_evp_t));
     cipher_evp_t *evp = ctx->evp;
 
     if (cipher == NULL) {
diff --git a/src/local.c b/src/local.c
index bed60f14..a02e881d 100644
--- a/src/local.c
+++ b/src/local.c
@@ -907,6 +907,9 @@ new_remote(int fd, int timeout)
     remote->buf                 = ss_malloc(sizeof(buffer_t));
     remote->recv_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->send_ctx            = ss_malloc(sizeof(remote_ctx_t));
+    balloc(remote->buf, BUF_SIZE);
+    memset(remote->recv_ctx, 0, sizeof(remote_ctx_t));
+    memset(remote->send_ctx, 0, sizeof(remote_ctx_t));
     remote->recv_ctx->connected = 0;
     remote->send_ctx->connected = 0;
     remote->fd                  = fd;
@@ -920,8 +923,6 @@ new_remote(int fd, int timeout)
     ev_timer_init(&remote->recv_ctx->watcher, remote_timeout_cb,
                   timeout, timeout);
 
-    balloc(remote->buf, BUF_SIZE);
-
     return remote;
 }
 
@@ -964,6 +965,9 @@ new_server(int fd, int method)
     server->recv_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->send_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->buf                 = ss_malloc(sizeof(buffer_t));
+    balloc(server->buf, BUF_SIZE);
+    memset(server->recv_ctx, 0, sizeof(server_ctx_t));
+    memset(server->send_ctx, 0, sizeof(server_ctx_t));
     server->stage               = STAGE_INIT;
     server->recv_ctx->connected = 0;
     server->send_ctx->connected = 0;
@@ -984,8 +988,6 @@ new_server(int fd, int method)
     ev_io_init(&server->recv_ctx->io, server_recv_cb, fd, EV_READ);
     ev_io_init(&server->send_ctx->io, server_send_cb, fd, EV_WRITE);
 
-    balloc(server->buf, BUF_SIZE);
-
     cork_dllist_add(&connections, &server->entries);
 
     return server;
@@ -1388,6 +1390,7 @@ main(int argc, char **argv)
     listen_ctx_t listen_ctx;
     listen_ctx.remote_num  = remote_num;
     listen_ctx.remote_addr = ss_malloc(sizeof(struct sockaddr *) * remote_num);
+    memset(listen_ctx.remote_addr, 0, sizeof(struct sockaddr *) * remote_num);
     for (i = 0; i < remote_num; i++) {
         char *host = remote_addr[i].host;
         char *port = remote_addr[i].port == NULL ? remote_port :
diff --git a/src/manager.c b/src/manager.c
index 7c05674e..f76c4dda 100644
--- a/src/manager.c
+++ b/src/manager.c
@@ -98,7 +98,7 @@ build_config(char *prefix, struct server *server)
     char *path    = NULL;
     int path_size = strlen(prefix) + strlen(server->port) + 20;
 
-    path = malloc(path_size);
+    path = ss_malloc(path_size);
     snprintf(path, path_size, "%s/.shadowsocks_%s.conf", prefix, server->port);
     FILE *f = fopen(path, "w+");
     if (f == NULL) {
@@ -243,7 +243,7 @@ get_server(char *buf, int len)
         return NULL;
     }
 
-    struct server *server = (struct server *)malloc(sizeof(struct server));
+    struct server *server = ss_malloc(sizeof(struct server));
     memset(server, 0, sizeof(struct server));
     if (obj->type == json_object) {
         int i = 0;
@@ -322,7 +322,7 @@ kill_server(char *prefix, char *pid_file)
 {
     char *path = NULL;
     int pid, path_size = strlen(prefix) + strlen(pid_file) + 2;
-    path = malloc(path_size);
+    path = ss_malloc(path_size);
     snprintf(path, path_size, "%s/%s", prefix, pid_file);
     FILE *f = fopen(path, "r");
     if (f == NULL) {
@@ -345,7 +345,7 @@ stop_server(char *prefix, char *port)
 {
     char *path = NULL;
     int pid, path_size = strlen(prefix) + strlen(port) + 20;
-    path = malloc(path_size);
+    path = ss_malloc(path_size);
     snprintf(path, path_size, "%s/.shadowsocks_%s.pid", prefix, port);
     FILE *f = fopen(path, "r");
     if (f == NULL) {
@@ -861,7 +861,7 @@ main(int argc, char **argv)
     struct passwd *pw   = getpwuid(getuid());
     const char *homedir = pw->pw_dir;
     working_dir_size = strlen(homedir) + 15;
-    working_dir      = malloc(working_dir_size);
+    working_dir      = ss_malloc(working_dir_size);
     snprintf(working_dir, working_dir_size, "%s/.shadowsocks", homedir);
 
     int err = mkdir(working_dir, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
@@ -894,7 +894,8 @@ main(int argc, char **argv)
 
     if (conf != NULL) {
         for (i = 0; i < conf->port_password_num; i++) {
-            struct server *server = (struct server *)malloc(sizeof(struct server));
+            struct server *server = ss_malloc(sizeof(struct server));
+            memset(server, 0, sizeof(struct server));
             strncpy(server->port, conf->port_password[i].port, 8);
             strncpy(server->password, conf->port_password[i].password, 128);
             add_server(&manager, server);
diff --git a/src/redir.c b/src/redir.c
index fdd7ce3b..eb8cb989 100644
--- a/src/redir.c
+++ b/src/redir.c
@@ -531,14 +531,15 @@ remote_send_cb(EV_P_ ev_io *w, int revents)
 static remote_t *
 new_remote(int fd, int timeout)
 {
-    remote_t *remote;
-    remote = ss_malloc(sizeof(remote_t));
-
+    remote_t *remote = ss_malloc(sizeof(remote_t));
     memset(remote, 0, sizeof(remote_t));
 
     remote->recv_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->send_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->buf                 = ss_malloc(sizeof(buffer_t));
+    balloc(remote->buf, BUF_SIZE);
+    memset(remote->recv_ctx, 0, sizeof(remote_ctx_t));
+    memset(remote->send_ctx, 0, sizeof(remote_ctx_t));
     remote->fd                  = fd;
     remote->recv_ctx->remote    = remote;
     remote->recv_ctx->connected = 0;
@@ -552,8 +553,6 @@ new_remote(int fd, int timeout)
     ev_timer_init(&remote->recv_ctx->watcher, remote_timeout_cb,
                   timeout, 0);
 
-    balloc(remote->buf, BUF_SIZE);
-
     return remote;
 }
 
@@ -590,12 +589,15 @@ close_and_free_remote(EV_P_ remote_t *remote)
 static server_t *
 new_server(int fd, int method)
 {
-    server_t *server;
-    server = ss_malloc(sizeof(server_t));
+    server_t *server = ss_malloc(sizeof(server_t));
+    memset(server, 0, sizeof(server_t));
 
     server->recv_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->send_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->buf                 = ss_malloc(sizeof(buffer_t));
+    balloc(server->buf, BUF_SIZE);
+    memset(server->recv_ctx, 0, sizeof(server_ctx_t));
+    memset(server->send_ctx, 0, sizeof(server_ctx_t));
     server->fd                  = fd;
     server->recv_ctx->server    = server;
     server->recv_ctx->connected = 0;
@@ -618,8 +620,6 @@ new_server(int fd, int method)
     ev_io_init(&server->recv_ctx->io, server_recv_cb, fd, EV_READ);
     ev_io_init(&server->send_ctx->io, server_send_cb, fd, EV_WRITE);
 
-    balloc(server->buf, BUF_SIZE);
-
     return server;
 }
 
@@ -981,6 +981,7 @@ main(int argc, char **argv)
     listen_ctx_t listen_ctx;
     listen_ctx.remote_num  = remote_num;
     listen_ctx.remote_addr = ss_malloc(sizeof(struct sockaddr *) * remote_num);
+    memset(listen_ctx.remote_addr, 0, sizeof(struct sockaddr *) * remote_num);
     for (int i = 0; i < remote_num; i++) {
         char *host = remote_addr[i].host;
         char *port = remote_addr[i].port == NULL ? remote_port :
diff --git a/src/resolv.c b/src/resolv.c
index f580d06d..7c694c05 100644
--- a/src/resolv.c
+++ b/src/resolv.c
@@ -266,8 +266,8 @@ dns_query_v4_cb(struct dns_ctx *ctx, struct dns_rr_a4 *result, void *data)
             cb_data->responses = new_responses;
 
             for (int i = 0; i < result->dnsa4_nrr; i++) {
-                struct sockaddr_in *sa =
-                    (struct sockaddr_in *)ss_malloc(sizeof(struct sockaddr_in));
+                struct sockaddr_in *sa = ss_malloc(sizeof(struct sockaddr_in));
+                memset(sa, 0, sizeof(struct sockaddr_in));
                 sa->sin_family = AF_INET;
                 sa->sin_port   = cb_data->port;
                 sa->sin_addr   = result->dnsa4_addr[i];
@@ -313,8 +313,8 @@ dns_query_v6_cb(struct dns_ctx *ctx, struct dns_rr_a6 *result, void *data)
             cb_data->responses = new_responses;
 
             for (int i = 0; i < result->dnsa6_nrr; i++) {
-                struct sockaddr_in6 *sa =
-                    (struct sockaddr_in6 *)ss_malloc(sizeof(struct sockaddr_in6));
+                struct sockaddr_in6 *sa = ss_malloc(sizeof(struct sockaddr_in6));
+                memset(sa, 0, sizeof(struct sockaddr_in6));
                 sa->sin6_family = AF_INET6;
                 sa->sin6_port   = cb_data->port;
                 sa->sin6_addr   = result->dnsa6_addr[i];
diff --git a/src/server.c b/src/server.c
index 726dd2cd..a850c7b0 100644
--- a/src/server.c
+++ b/src/server.c
@@ -969,7 +969,8 @@ server_recv_cb(EV_P_ ev_io *w, int revents)
                 ev_io_start(EV_A_ & remote->send_ctx->io);
             }
         } else {
-            query_t *query = (query_t *)ss_malloc(sizeof(query_t));
+            query_t *query = ss_malloc(sizeof(query_t));
+            memset(query, 0, sizeof(query_t));
             query->server = server;
             snprintf(query->hostname, 256, "%s", host);
 
@@ -1311,12 +1312,15 @@ new_remote(int fd)
         remote_conn++;
     }
 
-    remote_t *remote;
+    remote_t *remote = ss_malloc(sizeof(remote_t));
+    memset(remote, 0, sizeof(remote_t));
 
-    remote                      = ss_malloc(sizeof(remote_t));
     remote->recv_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->send_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->buf                 = ss_malloc(sizeof(buffer_t));
+    balloc(remote->buf, BUF_SIZE);
+    memset(remote->recv_ctx, 0, sizeof(remote_ctx_t));
+    memset(remote->send_ctx, 0, sizeof(remote_ctx_t));
     remote->fd                  = fd;
     remote->recv_ctx->remote    = remote;
     remote->recv_ctx->connected = 0;
@@ -1327,8 +1331,6 @@ new_remote(int fd)
     ev_io_init(&remote->recv_ctx->io, remote_recv_cb, fd, EV_READ);
     ev_io_init(&remote->send_ctx->io, remote_send_cb, fd, EV_WRITE);
 
-    balloc(remote->buf, BUF_SIZE);
-
     return remote;
 }
 
@@ -1378,6 +1380,10 @@ new_server(int fd, listen_ctx_t *listener)
     server->send_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->buf                 = ss_malloc(sizeof(buffer_t));
     server->header_buf          = ss_malloc(sizeof(buffer_t));
+    memset(server->recv_ctx, 0, sizeof(server_ctx_t));
+    memset(server->send_ctx, 0, sizeof(server_ctx_t));
+    balloc(server->buf, BUF_SIZE);
+    balloc(server->header_buf, BUF_SIZE);
     server->fd                  = fd;
     server->recv_ctx->server    = server;
     server->recv_ctx->connected = 0;
@@ -1406,10 +1412,7 @@ new_server(int fd, listen_ctx_t *listener)
     ev_timer_init(&server->recv_ctx->watcher, server_timeout_cb,
                   request_timeout, listener->timeout);
 
-    balloc(server->buf, BUF_SIZE);
-    balloc(server->header_buf, BUF_SIZE);
-
-    server->chunk = (chunk_t *)malloc(sizeof(chunk_t));
+    server->chunk = ss_malloc(sizeof(chunk_t));
     memset(server->chunk, 0, sizeof(chunk_t));
     server->chunk->buf = ss_malloc(sizeof(buffer_t));
     memset(server->chunk->buf, 0, sizeof(buffer_t));
diff --git a/src/tunnel.c b/src/tunnel.c
index c39d4227..4fb07710 100644
--- a/src/tunnel.c
+++ b/src/tunnel.c
@@ -502,14 +502,16 @@ remote_send_cb(EV_P_ ev_io *w, int revents)
 static remote_t *
 new_remote(int fd, int timeout)
 {
-    remote_t *remote;
-    remote = ss_malloc(sizeof(remote_t));
+    remote_t *remote = ss_malloc(sizeof(remote_t));
 
     memset(remote, 0, sizeof(remote_t));
 
     remote->buf                 = ss_malloc(sizeof(buffer_t));
     remote->recv_ctx            = ss_malloc(sizeof(remote_ctx_t));
     remote->send_ctx            = ss_malloc(sizeof(remote_ctx_t));
+    balloc(remote->buf, BUF_SIZE);
+    memset(remote->recv_ctx, 0, sizeof(remote_ctx_t));
+    memset(remote->send_ctx, 0, sizeof(remote_ctx_t));
     remote->fd                  = fd;
     remote->recv_ctx->remote    = remote;
     remote->recv_ctx->connected = 0;
@@ -521,8 +523,6 @@ new_remote(int fd, int timeout)
     ev_timer_init(&remote->send_ctx->watcher, remote_timeout_cb,
                   min(MAX_CONNECT_TIMEOUT, timeout), 0);
 
-    balloc(remote->buf, BUF_SIZE);
-
     return remote;
 }
 
@@ -558,12 +558,15 @@ close_and_free_remote(EV_P_ remote_t *remote)
 static server_t *
 new_server(int fd, int method)
 {
-    server_t *server;
+    server_t *server = ss_malloc(sizeof(server_t));
+    memset(server, 0, sizeof(server_t));
 
-    server                      = ss_malloc(sizeof(server_t));
     server->buf                 = ss_malloc(sizeof(buffer_t));
     server->recv_ctx            = ss_malloc(sizeof(server_ctx_t));
     server->send_ctx            = ss_malloc(sizeof(server_ctx_t));
+    balloc(server->buf, BUF_SIZE);
+    memset(server->recv_ctx, 0, sizeof(server_ctx_t));
+    memset(server->send_ctx, 0, sizeof(server_ctx_t));
     server->fd                  = fd;
     server->recv_ctx->server    = server;
     server->recv_ctx->connected = 0;
@@ -580,8 +583,6 @@ new_server(int fd, int method)
         server->d_ctx = NULL;
     }
 
-    balloc(server->buf, BUF_SIZE);
-
     ev_io_init(&server->recv_ctx->io, server_recv_cb, fd, EV_READ);
     ev_io_init(&server->send_ctx->io, server_send_cb, fd, EV_WRITE);
 
@@ -984,6 +985,7 @@ main(int argc, char **argv)
     listen_ctx.tunnel_addr = tunnel_addr;
     listen_ctx.remote_num  = remote_num;
     listen_ctx.remote_addr = ss_malloc(sizeof(struct sockaddr *) * remote_num);
+    memset(listen_ctx.remote_addr, 0, sizeof(struct sockaddr *) * remote_num);
     for (i = 0; i < remote_num; i++) {
         char *host = remote_addr[i].host;
         char *port = remote_addr[i].port == NULL ? remote_port :