fix(coverity/644326): NULL ptr deref in socket_address_is_tcp #38010

src/nvim/event/socket.c

@@ -23,24 +23,24 @@
 
 #include "event/socket.c.generated.h"
 
-/// Checks if an address string looks like a TCP endpoint.
+/// Checks if an address string looks like a TCP endpoint, and returns the end of the host part.
 ///
 /// @param address Address string
-/// @return true if address looks like a TCP endpoint, false otherwise
-bool socket_address_is_tcp(const char *address)
+/// @return pointer to the end of the host part of the address, or NULL if it is not a TCP address
+char *socket_address_tcp_host_end(const char *address)
 {
   if (address == NULL) {
-    return false;
+    return NULL;
   }
 
   // Windows drive letter path: "X:\..." or "X:/..." is a local path, not TCP.
   if (ASCII_ISALPHA((uint8_t)address[0]) && address[1] == ':'
       && (address[2] == '\\' || address[2] == '/')) {
-    return false;
+    return NULL;
   }
 
-  const char *colon = strrchr(address, ':');
-  return colon != NULL && colon != address;
+  char *colon = strrchr(address, ':');
+  return colon != NULL && colon != address ? colon : NULL;
 }
 
 int socket_watcher_init(Loop *loop, SocketWatcher *watcher, const char *endpoint)
@@ -48,9 +48,9 @@ int socket_watcher_init(Loop *loop, SocketWatcher *watcher, const char *endpoint
 {
   xstrlcpy(watcher->addr, endpoint, sizeof(watcher->addr));
   char *addr = watcher->addr;
-  char *host_end = strrchr(addr, ':');
+  char *host_end = socket_address_tcp_host_end(addr);
 
-  if (socket_address_is_tcp(addr)) {
+  if (host_end) {
     // Split user specified address into two strings, addr (hostname) and port.
     // The port part in watcher->addr will be updated later.
     *host_end = NUL;

src/nvim/main.c

@@ -928,7 +928,7 @@ static uint64_t server_connect(char *server_addr, const char **errmsg)
   }
   CallbackReader on_data = CALLBACK_READER_INIT;
   const char *error = NULL;
-  bool is_tcp = socket_address_is_tcp(server_addr);
+  bool is_tcp = socket_address_tcp_host_end(server_addr) != NULL;
   // connected to channel
   uint64_t chan = channel_connect(is_tcp, server_addr, true, on_data, 500, &error);
   if (error) {

src/nvim/ui_client.c

@@ -298,7 +298,7 @@ static void channel_connect_event(void **argv)
   char *server_addr = argv[0];
 
   const char *err = "";
-  bool is_tcp = socket_address_is_tcp(server_addr);
+  bool is_tcp = socket_address_tcp_host_end(server_addr) != NULL;
   CallbackReader on_data = CALLBACK_READER_INIT;
   uint64_t chan = channel_connect(is_tcp, server_addr, true, on_data, 50, &err);