virtio: Fix memory leaks reported by Coverity

All four leaks are similar, so fix them in one patch.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/9pfs/virtio-9p-local.c

@@ -488,7 +488,7 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char *buffer;
+    char *buffer = NULL;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
@@ -499,7 +499,6 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         err = local_set_xattr(buffer, credp);
@@ -512,7 +511,6 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         err = local_set_mapped_file_attr(fs_ctx, path, credp);
@@ -525,7 +523,6 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mknod(buffer, credp->fc_mode, credp->fc_rdev);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         err = local_post_create_passthrough(fs_ctx, path, credp);
@@ -539,8 +536,8 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
 err_end:
     remove(buffer);
     errno = serrno;
-    g_free(buffer);
 out:
+    g_free(buffer);
     v9fs_string_free(&fullname);
     return err;
 }
@@ -552,7 +549,7 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char *buffer;
+    char *buffer = NULL;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
@@ -563,7 +560,6 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFDIR;
@@ -576,7 +572,6 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         credp->fc_mode = credp->fc_mode|S_IFDIR;
@@ -590,7 +585,6 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
         buffer = rpath(fs_ctx, path);
         err = mkdir(buffer, credp->fc_mode);
         if (err == -1) {
-            g_free(buffer);
             goto out;
         }
         err = local_post_create_passthrough(fs_ctx, path, credp);
@@ -604,8 +598,8 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
 err_end:
     remove(buffer);
     errno = serrno;
-    g_free(buffer);
 out:
+    g_free(buffer);
     v9fs_string_free(&fullname);
     return err;
 }
@@ -659,7 +653,7 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     int err = -1;
     int serrno = 0;
     V9fsString fullname;
-    char *buffer;
+    char *buffer = NULL;
 
     /*
      * Mark all the open to not follow symlinks
@@ -675,7 +669,6 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
         buffer = rpath(fs_ctx, path);
         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
-            g_free(buffer);
             err = fd;
             goto out;
         }
@@ -690,7 +683,6 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
         buffer = rpath(fs_ctx, path);
         fd = open(buffer, flags, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
-            g_free(buffer);
             err = fd;
             goto out;
         }
@@ -706,7 +698,6 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
         buffer = rpath(fs_ctx, path);
         fd = open(buffer, flags, credp->fc_mode);
         if (fd == -1) {
-            g_free(buffer);
             err = fd;
             goto out;
         }
@@ -724,8 +715,8 @@ err_end:
     close(fd);
     remove(buffer);
     errno = serrno;
-    g_free(buffer);
 out:
+    g_free(buffer);
     v9fs_string_free(&fullname);
     return err;
 }
@@ -738,7 +729,7 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
     int serrno = 0;
     char *newpath;
     V9fsString fullname;
-    char *buffer;
+    char *buffer = NULL;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
@@ -751,7 +742,6 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         buffer = rpath(fs_ctx, newpath);
         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
-            g_free(buffer);
             err = fd;
             goto out;
         }
@@ -781,7 +771,6 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         buffer = rpath(fs_ctx, newpath);
         fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS);
         if (fd == -1) {
-            g_free(buffer);
             err = fd;
             goto out;
         }
@@ -810,7 +799,6 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
         buffer = rpath(fs_ctx, newpath);
         err = symlink(oldpath, buffer);
         if (err) {
-            g_free(buffer);
             goto out;
         }
         err = lchown(buffer, credp->fc_uid, credp->fc_gid);
@@ -831,8 +819,8 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
 err_end:
     remove(buffer);
     errno = serrno;
-    g_free(buffer);
 out:
+    g_free(buffer);
     v9fs_string_free(&fullname);
     return err;
 }