Fixes file descriptor leak when parser ends with error.

Thanks to MrBr for the bugreport.

3 files changed, 31 insertions, 5 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index b1bbeae2..99785057 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -275,9 +275,6 @@ cf_hash(byte *c)
  * match - these do not have fd and flex buffer yet).
  *
  * FIXME: Most of these ifs and include functions are really sysdep/unix.
- *
- * FIXME: Resources (fd, flex buffers and glob data) in IFS stack
- * are not freed when cf_error() is called.
  */
 
 static struct include_file_stack *
@@ -316,13 +313,36 @@ enter_ifs(struct include_file_stack *new)
   yy_switch_to_buffer(new->buffer);
 }
 
+/**
+ * cf_lex_unwind - unwind lexer state during error
+ *
+ * cf_lex_unwind() frees the internal state on IFS stack when the lexical
+ * analyzer is terminated by cf_error().
+ */
+void
+cf_lex_unwind(void)
+{
+  struct include_file_stack *n;
+
+  for (n = ifs; n != ifs_head; n = n->prev)
+    {
+      /* Memory is freed automatically */
+      if (n->buffer)
+	yy_delete_buffer(n->buffer);
+      if (n->fd)
+        close(n->fd);
+    }
+
+  ifs = ifs_head;
+}
+
 static void
 cf_include(char *arg, int alen)
 {
   struct include_file_stack *base_ifs = ifs;
   int new_depth, rv, i;
   char *patt;
-  glob_t g;
+  glob_t g = {};
 
   new_depth = ifs->depth + 1;
   if (new_depth > MAX_INCLUDE_DEPTH)
@@ -370,7 +390,10 @@ cf_include(char *arg, int alen)
       struct stat fs;
 
       if (stat(fname, &fs) < 0)
-        cf_error("Unable to stat included file %s: %m", fname);
+	{
+	  globfree(&g);
+	  cf_error("Unable to stat included file %s: %m", fname);
+	}
 
       if (fs.st_mode & S_IFDIR)
         continue;
diff --git a/conf/conf.c b/conf/conf.c
index 67b027ce..a907402d 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -502,6 +502,7 @@ cf_error(char *msg, ...)
   new_config->err_msg = cfg_strdup(buf);
   new_config->err_lino = ifs->lino;
   new_config->err_file_name = ifs->file_name;
+  cf_lex_unwind();
   longjmp(conf_jmpbuf, 1);
 }
 
diff --git a/conf/conf.h b/conf/conf.h
index a8bba7e8..fa14d7b5 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -139,6 +139,8 @@ extern struct include_file_stack *ifs;
 
 int cf_lex(void);
 void cf_lex_init(int is_cli, struct config *c);
+void cf_lex_unwind(void);
+
 struct symbol *cf_find_symbol(byte *c);
 struct symbol *cf_default_name(char *template, int *counter);
 struct symbol *cf_define_symbol(struct symbol *symbol, int type, void *def);