utils: fix lxc_string_split()

Make sure we don't return uninitialized memory.

Signed-off-by: Christian Brauner <christian.brauner@canonical.com>

diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index 9a6ef4b37528f1cb9460164db8d380b4decff15a..c72c26a50896bfddcdf755e8589d90b8159883da 100644 (file)
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -774,8 +774,8 @@ bool lxc_string_in_list(const char *needle, const char *haystack, char _sep)
 char **lxc_string_split(const char *string, char _sep)
 {
        char *token, *str, *saveptr = NULL;
-       char sep[2] = { _sep, '\0' };
-       char **result = NULL;
+       char sep[2] = {_sep, '\0'};
+       char **tmp = NULL, **result = NULL;
        size_t result_capacity = 0;
        size_t result_count = 0;
        int r, saved_errno;
@@ -783,7 +783,7 @@ char **lxc_string_split(const char *string, char _sep)
        if (!string)
                return calloc(1, sizeof(char *));
 
-       str = alloca(strlen(string)+1);
+       str = alloca(strlen(string) + 1);
        strcpy(str, string);
        for (; (token = strtok_r(str, sep, &saveptr)); str = NULL) {
                r = lxc_grow_array((void ***)&result, &result_capacity, result_count + 1, 16);
@@ -796,7 +796,14 @@ char **lxc_string_split(const char *string, char _sep)
        }
 
        /* if we allocated too much, reduce it */
-       return realloc(result, (result_count + 1) * sizeof(char *));
+       tmp = realloc(result, (result_count + 1) * sizeof(char *));
+       if (!tmp)
+               goto error_out;
+       result = tmp;
+       /* Make sure we don't return uninitialized memory. */
+       if (result_count == 0)
+               *result = NULL;
+       return result;
 error_out:
        saved_errno = errno;
        lxc_free_array((void **)result, free);