Check return values from calloc (found by Coverity).

Error: NULL_RETURNS:
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:417: returned_null: Function "calloc" returns null (checked 67 out of 81 times).
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:417: var_assigned: Assigning: "ret" = null return value from "calloc".
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:418: dereference: Dereferencing a null pointer "ret".
[...]
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:374: returned_null: Function "calloc" returns null (checked 67 out of 81 times).
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:374: var_assigned: Assigning: "ret" = null return value from "calloc".
/builddir/build/BUILD/libguestfs-1.16.5/src/inspect.c:375: dereference: Dereferencing a null pointer "ret".

1 files changed, 29 insertions, 25 deletions

diff --git a/src/inspect.c b/src/inspect.c
index d3bb76a4..4a4871f4 100644
--- a/src/inspect.c
+++ b/src/inspect.c
@@ -371,23 +371,20 @@ guestfs__inspect_get_mountpoints (guestfs_h *g, const char *root)
   if (!fs)
     return NULL;
 
+#define CRITERION(fs, i) fs->fstab[i].mountpoint[0] == '/'
+
   char **ret;
+  size_t i, count, nr = fs->nr_fstab;
 
-  /* If no fstab information (Windows) return just the root. */
-  if (fs->nr_fstab == 0) {
-    ret = calloc (3, sizeof (char *));
-    ret[0] = safe_strdup (g, "/");
-    ret[1] = safe_strdup (g, root);
-    ret[2] = NULL;
-    return ret;
+  if (nr == 0)
+    count = 1;
+  else {
+    count = 0;
+    for (i = 0; i < nr; ++i)
+      if (CRITERION (fs, i))
+        count++;
   }
 
-#define CRITERION fs->fstab[i].mountpoint[0] == '/'
-  size_t i, count = 0;
-  for (i = 0; i < fs->nr_fstab; ++i)
-    if (CRITERION)
-      count++;
-
   /* Hashtables have 2N+1 entries. */
   ret = calloc (2*count+1, sizeof (char *));
   if (ret == NULL) {
@@ -395,9 +392,17 @@ guestfs__inspect_get_mountpoints (guestfs_h *g, const char *root)
     return NULL;
   }
 
+  /* If no fstab information (Windows) return just the root. */
+  if (nr == 0) {
+    ret[0] = safe_strdup (g, "/");
+    ret[1] = safe_strdup (g, root);
+    ret[2] = NULL;
+    return ret;
+  }
+
   count = 0;
-  for (i = 0; i < fs->nr_fstab; ++i)
-    if (CRITERION) {
+  for (i = 0; i < nr; ++i)
+    if (CRITERION (fs, i)) {
       ret[2*count] = safe_strdup (g, fs->fstab[i].mountpoint);
       ret[2*count+1] = safe_strdup (g, fs->fstab[i].device);
       count++;
@@ -415,23 +420,22 @@ guestfs__inspect_get_filesystems (guestfs_h *g, const char *root)
     return NULL;
 
   char **ret;
+  size_t i, nr = fs->nr_fstab;
+
+  ret = calloc (nr == 0 ? 2 : nr+1, sizeof (char *));
+  if (ret == NULL) {
+    perrorf (g, "calloc");
+    return NULL;
+  }
 
   /* If no fstab information (Windows) return just the root. */
-  if (fs->nr_fstab == 0) {
-    ret = calloc (2, sizeof (char *));
+  if (nr == 0) {
     ret[0] = safe_strdup (g, root);
     ret[1] = NULL;
     return ret;
   }
 
-  ret = calloc (fs->nr_fstab + 1, sizeof (char *));
-  if (ret == NULL) {
-    perrorf (g, "calloc");
-    return NULL;
-  }
-
-  size_t i;
-  for (i = 0; i < fs->nr_fstab; ++i)
+  for (i = 0; i < nr; ++i)
     ret[i] = safe_strdup (g, fs->fstab[i].device);
 
   return ret;