Only advance kernel version when the booted partition has a valid key block

firmware/lib/vboot_kernel.c

-/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+/* Copyright (c) 2010-2011 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Functions for loading a kernel from disk.
  * (Firmware portion)
  */
 
 #include "vboot_kernel.h"
 
 #include "boot_device.h"
@@ skipping 438 matching lines @@
     Free(kbuf);
 
   /* Write and free GPT data */
   WriteAndFreeGptData(&gpt);
 
   /* Handle finding a good partition */
   if (good_partition >= 0) {
     VBDEBUG(("Good_partition >= 0\n"));
 
     /* See if we need to update the TPM */
-    if (kBootRecovery != boot_mode) {
+    if (kBootRecovery != boot_mode && good_partition_key_block_valid) {
       /* We only update the TPM in normal and developer boot modes.  In
        * developer mode, we only advanced lowest_version for kernels with valid
        * key blocks, and didn't count self-signed key blocks.  In recovery
        * mode, the TPM stays PP-unlocked, so anything we write gets blown away
        * by the firmware when we go back to normal mode. */
       VBDEBUG(("Boot_flags = not recovery\n"));
       if (lowest_version > tpm_version) {
         status = RollbackKernelWrite((uint32_t)lowest_version);
         if (0 != status) {
           VBDEBUG(("Error writing kernel versions to TPM.\n"));
@@ skipping 29 matching lines @@
   /* Save whether the good partition's key block was fully verified */
   VbNvSet(vnc, VBNV_FW_VERIFIED_KERNEL_KEY, good_partition_key_block_valid);
 
   /* Store recovery request, if any, then tear down non-volatile storage */
   VbNvSet(vnc, VBNV_RECOVERY_REQUEST, LOAD_KERNEL_RECOVERY == retval ?
           recovery : VBNV_RECOVERY_NOT_REQUESTED);
   VbNvTeardown(vnc);
 
   return retval;
 }