diff options
Diffstat (limited to 'firmware/lib/vboot_api_kernel.c')
| -rw-r--r-- | firmware/lib/vboot_api_kernel.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/firmware/lib/vboot_api_kernel.c b/firmware/lib/vboot_api_kernel.c index 2cc1a88b..1879b845 100644 --- a/firmware/lib/vboot_api_kernel.c +++ b/firmware/lib/vboot_api_kernel.c @@ -188,6 +188,7 @@ VbError_t VbBootNormal(struct vb2_context *ctx, VbCommonParams *cparams) { VbSharedDataHeader *shared = (VbSharedDataHeader *)cparams->shared_data_blob; + uint32_t max_rollforward; /* Boot from fixed disk only */ VB2_DEBUG("Entering\n"); @@ -224,6 +225,25 @@ VbError_t VbBootNormal(struct vb2_context *ctx, VbCommonParams *cparams) return rv; } + /* Limit kernel version rollforward if needed */ + if (0 == VbNvGet(&vnc, VBNV_KERNEL_MAX_ROLLFORWARD, &max_rollforward)) { + /* + * Can't limit kernel version to less than the version + * currently in the TPM. That is, we're limiting rollforward, + * not allowing rollback. + */ + if (max_rollforward < shared->kernel_version_tpm_start) + max_rollforward = shared->kernel_version_tpm_start; + + if (shared->kernel_version_tpm > max_rollforward) { + VB2_DEBUG("Limiting TPM kernel version roll-forward " + "to 0x%x < 0x%x\n", + max_rollforward, shared->kernel_version_tpm); + + shared->kernel_version_tpm = max_rollforward; + } + } + if ((shared->kernel_version_tpm > shared->kernel_version_tpm_start) && RollbackKernelWrite(shared->kernel_version_tpm)) { VB2_DEBUG("Error writing kernel versions to TPM.\n"); |