mkfs.ubifs: Improve error handling of is_contained()

The is_contained() function returns -1 if an error occurs when
canonicalizing the output file path/root directory. This resulted in the
confusing error message 'Error: The output file cannot be in the UBIFS
root' when specifying a non-existent directory for the output.
This patch changes the error handling to display a different error
message for the case when is_contained() returns -1.
Additionally it frees all memory allocated by is_contained().

Signed-off-by: Marcus Prebble <marcus.prebble@axis.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --git a/mkfs.ubifs/mkfs.ubifs.c b/mkfs.ubifs/mkfs.ubifs.c
index 5b433bd512a3c364c22dc672702e884104da575f..2bb819e297f402c94e90b377914d7cfdcf3545ed 100644 (file)
--- a/mkfs.ubifs/mkfs.ubifs.c
+++ b/mkfs.ubifs/mkfs.ubifs.c
@@ -245,7 +245,10 @@ static char *make_path(const char *dir, const char *name)
  */
 static int is_contained(const char *file, const char *dir)
 {
-       char *file_base, *copy, *real_file, *real_dir, *p;
+       char *real_file = NULL;
+       char *real_dir = NULL;
+       char *file_base, *copy;
+       int ret = -1;
 
        /* Make a copy of the file path because 'dirname()' can modify it */
        copy = strdup(file);
@@ -255,31 +258,29 @@ static int is_contained(const char *file, const char *dir)
 
        /* Turn the paths into the canonical form */
        real_file = malloc(PATH_MAX);
-       if (!real_file) {
-               free(copy);
-               return -1;
-       }
+       if (!real_file)
+               goto out_free;
 
        real_dir = malloc(PATH_MAX);
-       if (!real_dir) {
-               free(real_file);
-               free(copy);
-               return -1;
-       }
+       if (!real_dir)
+               goto out_free;
+
        if (!realpath(file_base, real_file)) {
-               perror("realpath");
-               return -1;
+               perror("Could not canonicalize file path");
+               goto out_free;
        }
        if (!realpath(dir, real_dir)) {
-               perror("realpath");
-               return -1;
+               perror("Could not canonicalize directory");
+               goto out_free;
        }
 
-       p = strstr(real_file, real_dir);
-       free(real_dir);
-       free(real_file);
+       ret = !!strstr(real_file, real_dir);
+
+out_free:
        free(copy);
-       return !!p;
+       free(real_file);
+       free(real_dir);
+       return ret;
 }
 
 /**
@@ -334,9 +335,14 @@ static int validate_options(void)
 
        if (!output)
                return err_msg("no output file or UBI volume specified");
-       if (root && is_contained(output, root))
-               return err_msg("output file cannot be in the UBIFS root "
-                              "directory");
+       if (root) {
+               tmp = is_contained(output, root);
+               if (tmp < 0)
+                       return err_msg("failed to perform output file root check");
+               else if (tmp)
+                       return err_msg("output file cannot be in the UBIFS root "
+                                      "directory");
+       }
        if (!is_power_of_2(c->min_io_size))
                return err_msg("min. I/O unit size should be power of 2");
        if (c->leb_size < c->min_io_size)