criu: fix gcc-8 warnings

criu/sk-packet.c:443:3: error: 'strncpy' output may be truncated
copying 14 bytes from a string of length 15
   strncpy(addr_spkt.sa_data, req.ifr_name, sa_data_size);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/img-remote.c:383:3: error: 'strncpy' specified bound 4096
equals destination size
   strncpy(snapshot_id, li->snapshot_id, PATHLEN);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/img-remote.c:384:3: error: 'strncpy' specified bound 4096
equals destination size
   strncpy(path, li->name, PATHLEN);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/files.c:288:3: error: 'strncpy' output may be truncated copying
4095 bytes from a string of length 4096
   strncpy(buf, link->name, PATH_MAX - 1);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/sk-unix.c:239:36: error: '/' directive output may be truncated
writing 1 byte into a region of size between 0 and 4095
   snprintf(path, sizeof(path), ".%s/%s", dir, sk->name);
                                    ^
criu/sk-unix.c:239:3: note: 'snprintf' output 3 or more bytes
(assuming 4098) into a destination of size 4096
   snprintf(path, sizeof(path), ".%s/%s", dir, sk->name);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/mount.c:2563:3: error: 'strncpy' specified bound 4096 equals
destination size
   strncpy(path, m->mountpoint, PATH_MAX);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
criu/cr-restore.c:3647:2: error: 'strncpy' specified bound 16 equals
destination size
  strncpy(task_args->comm, core->tc->comm, sizeof(task_args->comm));
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/cr-restore.c

@@ -3337,7 +3337,8 @@ static int sigreturn_restore(pid_t pid, struct task_restore_args *task_args, uns
 	log_get_logstart(&task_args->logstart);
 	task_args->sigchld_act	= sigchld_act;
 
-	strncpy(task_args->comm, core->tc->comm, sizeof(task_args->comm));
+	strncpy(task_args->comm, core->tc->comm, TASK_COMM_LEN - 1);
+	task_args->comm[TASK_COMM_LEN - 1] = 0;
 
 	/*
 	 * Fill up per-thread data.

criu/files.c

@@ -284,7 +284,8 @@ static int fixup_overlayfs(struct fd_parms *p, struct fd_link *link)
 		char buf[PATH_MAX];
 		int n;
 
-		strncpy(buf, link->name, PATH_MAX - 1);
+		strncpy(buf, link->name, PATH_MAX);
+		buf[PATH_MAX - 1] = 0;
 		n = snprintf(link->name, PATH_MAX, "%s/%s", m->mountpoint, buf + 2);
 		if (n >= PATH_MAX) {
 			pr_err("Not enough space to replace %s\n", buf);

criu/include/files.h

@@ -25,7 +25,7 @@ struct fd_link {
 	union {
 		/* Link info for generic file (path) */
 		struct {
-			char	name[PATH_MAX + 1];
+			char	name[PATH_MAX];
 			size_t	len;
 		};
 

criu/mount.c

@@ -2560,7 +2560,8 @@ static int fixup_remap_mounts()
 		char path[PATH_MAX];
 		int len;
 
-		strncpy(path, m->mountpoint, PATH_MAX);
+		strncpy(path, m->mountpoint, PATH_MAX - 1);
+		path[PATH_MAX - 1] = 0;
 		len = print_ns_root(m->nsid, 0, path, PATH_MAX);
 		path[len] = '/';
 

criu/sk-packet.c

@@ -440,7 +440,7 @@ static int open_packet_sk_spkt(PacketSockEntry *pse, int *new_fd)
 			goto err;
 		}
 
-		strncpy(addr_spkt.sa_data, req.ifr_name, sa_data_size);
+		memcpy(addr_spkt.sa_data, req.ifr_name, sa_data_size);
 		addr_spkt.sa_data[sa_data_size - 1] = 0;
 
 		if (bind(sk, &addr_spkt, sizeof(addr_spkt)) < 0) {

criu/sk-unix.c

@@ -238,7 +238,10 @@ static int resolve_rel_name(struct unix_sk_desc *sk, const struct fd_parms *p)
 		}
 		dir[ret] = 0;
 
-		snprintf(path, sizeof(path), ".%s/%s", dir, sk->name);
+		if (snprintf(path, sizeof(path), ".%s/%s", dir, sk->name) >= sizeof(path)) {
+			pr_err("The path .%s/%s is too long", dir, sk->name);
+			goto err;
+		}
 		if (fstatat(mntns_root, path, &st, 0)) {
 			if (errno == ENOENT)
 				continue;

lib/c/criu.c

@@ -1075,9 +1075,16 @@ static int criu_connect(criu_opts *opts, bool d)
 	memset(&addr, 0, sizeof(addr));
 	addr.sun_family = AF_LOCAL;
 
-	strncpy(addr.sun_path, opts->service_address, sizeof(addr.sun_path));
+	addr_len = strlen(opts->service_address);
+	if (addr_len >= sizeof(addr.sun_path)) {
+		fprintf(stderr, "The service address %s is too long",
+					opts->service_address);
+		close(fd);
+		return -1;
+	}
+	memcpy(addr.sun_path, opts->service_address, addr_len);
 
-	addr_len = strlen(opts->service_address) + sizeof(addr.sun_family);
+	addr_len += sizeof(addr.sun_family);
 
 	ret = connect(fd, (struct sockaddr *) &addr, addr_len);
 	if (ret < 0) {