pam_cgfs: make sure that **p is not NULL

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

diff --git a/pam/pam_cgfs.c b/pam/pam_cgfs.c
index a22d2f8e9dbdb42037621318cd8f08e1964b05fd..fd47d7076a2271a1997eb164c9fdf2a3d2a2e184 100644 (file)
--- a/pam/pam_cgfs.c
+++ b/pam/pam_cgfs.c
@@ -1649,6 +1649,9 @@ static char *string_join(const char *sep, const char **parts, bool use_as_prefix
        size_t sep_len = strlen(sep);
        size_t result_len = use_as_prefix * sep_len;
 
+       if (!parts)
+               return NULL;
+
        /* calculate new string length */
        for (p = (char **)parts; *p; p++)
                result_len += (p > (char **)parts) * sep_len + strlen(*p);