fish options parsing: Allow add_drives to be called multiple times.

Ensure that the drv structure is always zeroed on allocation.

Don't leak old drv->device when add_drives is called multiple times.

3 files changed, 11 insertions, 10 deletions

diff --git a/fish/fish.c b/fish/fish.c
index b782b7cb..3cf15b20 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -341,13 +341,12 @@ main (int argc, char *argv[])
         list_prepared_drives ();
         exit (EXIT_SUCCESS);
       }
-      drv = malloc (sizeof (struct drv));
+      drv = calloc (1, sizeof (struct drv));
       if (!drv) {
         perror ("malloc");
         exit (EXIT_FAILURE);
       }
       drv->type = drv_N;
-      drv->device = NULL;
       drv->nr_drives = -1;
       if (asprintf (&drv->N.filename, "test%d.img",
                     next_prepared_drive++) == -1) {
@@ -415,18 +414,17 @@ main (int argc, char *argv[])
     while (optind < argc) {
       if (strchr (argv[optind], '/') ||
           access (argv[optind], F_OK) == 0) { /* simulate -a option */
-        drv = malloc (sizeof (struct drv));
+        drv = calloc (1, sizeof (struct drv));
         if (!drv) {
           perror ("malloc");
           exit (EXIT_FAILURE);
         }
         drv->type = drv_a;
         drv->a.filename = argv[optind];
-        drv->a.format = NULL;
         drv->next = drvs;
         drvs = drv;
       } else {                  /* simulate -d option */
-        drv = malloc (sizeof (struct drv));
+        drv = calloc (1, sizeof (struct drv));
         if (!drv) {
           perror ("malloc");
           exit (EXIT_FAILURE);
diff --git a/fish/options.c b/fish/options.c
index 48c8e1c2..f6523898 100644
--- a/fish/options.c
+++ b/fish/options.c
@@ -43,6 +43,9 @@ add_drives (struct drv *drv, char next_drive)
   if (drv) {
     next_drive = add_drives (drv->next, next_drive);
 
+    free (drv->device);
+    drv->device = NULL;
+
     if (asprintf (&drv->device, "/dev/sd%c", next_drive) == -1) {
       perror ("asprintf");
       exit (EXIT_FAILURE);
diff --git a/fish/options.h b/fish/options.h
index 9b9aee5e..7411a2ab 100644
--- a/fish/options.h
+++ b/fish/options.h
@@ -75,7 +75,9 @@ extern int echo_keys;
 extern const char *libvirt_uri;
 extern const char *program_name;
 
-/* List of drives added via -a, -d or -N options. */
+/* List of drives added via -a, -d or -N options.  NB: Unused fields
+ * in this struct MUST be zeroed, ie. use calloc, not malloc.
+ */
 struct drv {
   struct drv *next;
 
@@ -139,13 +141,12 @@ extern int add_libvirt_drives (const char *guest);
     perror (optarg);                            \
     exit (EXIT_FAILURE);                        \
   }                                             \
-  drv = malloc (sizeof (struct drv));           \
+  drv = calloc (1, sizeof (struct drv));        \
   if (!drv) {                                   \
     perror ("malloc");                          \
     exit (EXIT_FAILURE);                        \
   }                                             \
   drv->type = drv_a;                            \
-  drv->device = NULL;                           \
   drv->nr_drives = -1;                          \
   drv->a.filename = optarg;                     \
   drv->a.format = format;                       \
@@ -156,13 +157,12 @@ extern int add_libvirt_drives (const char *guest);
   libvirt_uri = optarg
 
 #define OPTION_d                                \
-  drv = malloc (sizeof (struct drv));           \
+  drv = calloc (1, sizeof (struct drv));        \
   if (!drv) {                                   \
     perror ("malloc");                          \
     exit (EXIT_FAILURE);                        \
   }                                             \
   drv->type = drv_d;                            \
-  drv->device = NULL;                           \
   drv->nr_drives = -1;                          \
   drv->d.guest = optarg;                        \
   drv->next = drvs;                             \