Fix bugs found by clang analyzer

libssh/kex.c

@@ -202,7 +202,7 @@ char **space_tokenize(const char *chain){
 
 /* find_matching gets 2 parameters : a list of available objects (available_d), separated by colons,*/
 /* and a list of preferred objects (preferred_d) */
-/* it will return a strduped pointer on the first prefered object found in the available objects list */
+/* it will return a strduped pointer on the first preferred object found in the available objects list */
 
 char *ssh_find_matching(const char *available_d, const char *preferred_d){
     char ** tok_available, **tok_preferred;
@@ -222,6 +222,7 @@ char *ssh_find_matching(const char *available_d, const char *preferred_d){
     if (tok_preferred == NULL) {
       SAFE_FREE(tok_available[0]);
       SAFE_FREE(tok_available);
+      return NULL;
     }
 
     for(i_pref=0; tok_preferred[i_pref] ; ++i_pref){
@@ -230,18 +231,18 @@ char *ssh_find_matching(const char *available_d, const char *preferred_d){
           /* match */
           ret=strdup(tok_available[i_avail]);
           /* free the tokens */
-          free(tok_available[0]);
-          free(tok_preferred[0]);
-          free(tok_available);
-          free(tok_preferred);
+          SAFE_FREE(tok_available[0]);
+          SAFE_FREE(tok_preferred[0]);
+          SAFE_FREE(tok_available);
+          SAFE_FREE(tok_preferred);
           return ret;
         }
       }
     }
-    free(tok_available[0]);
-    free(tok_preferred[0]);
-    free(tok_available);
-    free(tok_preferred);
+    SAFE_FREE(tok_available[0]);
+    SAFE_FREE(tok_preferred[0]);
+    SAFE_FREE(tok_available);
+    SAFE_FREE(tok_preferred);
     return NULL;
 }
 

libssh/keyfiles.c

@@ -593,12 +593,13 @@ static int pem_get_password(char *buf, int size, int rwflag, void *userdata) {
 
   /* unused flag */
   (void) rwflag;
-
-  ZERO_STRUCTP(buf);
+  if(buf==NULL)
+    return 0;
+  memset(buf,'\0',size);
   ssh_log(session, SSH_LOG_RARE,
       "Trying to call external authentication function");
 
-  if (session && session->callbacks->auth_function) {
+  if (session && session->callbacks && session->callbacks->auth_function) {
     if (session->callbacks->auth_function("Passphrase for private key:", buf, size, 0, 0,
         session->callbacks->userdata) < 0) {
       return 0;

libssh/sftp.c

@@ -104,12 +104,10 @@ static void sftp_ext_free(sftp_ext ext) {
 sftp_session sftp_new(ssh_session session){
   sftp_session sftp;
 
-  enter_function();
-
   if (session == NULL) {
-    leave_function();
     return NULL;
   }
+  enter_function();
 
   sftp = malloc(sizeof(struct sftp_session_struct));
   if (sftp == NULL) {
@@ -123,7 +121,7 @@ sftp_session sftp_new(ssh_session session){
   if (sftp->ext == NULL) {
     ssh_set_error_oom(session);
     SAFE_FREE(sftp);
-    sftp_leave_function();
+    leave_function();
     return NULL;
   }