diff options
Diffstat (limited to 'firmware/lib/rollback_index.c')
| -rw-r--r-- | firmware/lib/rollback_index.c | 43 |
1 files changed, 19 insertions, 24 deletions
diff --git a/firmware/lib/rollback_index.c b/firmware/lib/rollback_index.c index b7549bba..b0d4eb58 100644 --- a/firmware/lib/rollback_index.c +++ b/firmware/lib/rollback_index.c @@ -141,6 +141,22 @@ vb2_error_t SetVirtualDevMode(int val) uint32_t ReadSpaceKernel(RollbackSpaceKernel *rsk) { +#ifndef TPM2_MODE + /* + * Before reading the kernel space, verify its permissions. If the + * kernel space has the wrong permission, we give up. This will need + * to be fixed by the recovery kernel. We will have to worry about + * this because at any time (even with PP turned off) the TPM owner can + * remove and redefine a PP-protected space (but not write to it). + */ + uint32_t perms; + + RETURN_ON_FAILURE(TlclGetPermissions(KERNEL_NV_INDEX, &perms)); + + if (perms != TPM_NV_PER_PPWRITE) + return TPM_E_CORRUPTED_STATE; +#endif + uint32_t r; r = TlclRead(KERNEL_NV_INDEX, rsk, sizeof(RollbackSpaceKernel)); @@ -153,6 +169,9 @@ uint32_t ReadSpaceKernel(RollbackSpaceKernel *rsk) if (rsk->struct_version < ROLLBACK_SPACE_FIRMWARE_VERSION) return TPM_E_STRUCT_VERSION; + if (rsk->uid != ROLLBACK_SPACE_KERNEL_UID) + return TPM_E_CORRUPTED_STATE; + if (rsk->crc8 != vb2_crc8(rsk, offsetof(RollbackSpaceKernel, crc8))) { VB2_DEBUG("TPM: bad secdatak CRC\n"); return TPM_E_CORRUPTED_STATE; @@ -207,31 +226,7 @@ uint32_t RollbackFwmpRead(struct RollbackSpaceFwmp *fwmp) uint32_t RollbackKernelRead(uint32_t* version) { RollbackSpaceKernel rsk; - - /* - * Read the kernel space and verify its permissions. If the kernel - * space has the wrong permission, or it doesn't contain the right - * identifier, we give up. This will need to be fixed by the - * recovery kernel. We have to worry about this because at any time - * (even with PP turned off) the TPM owner can remove and redefine a - * PP-protected space (but not write to it). - */ RETURN_ON_FAILURE(ReadSpaceKernel(&rsk)); -#ifndef TPM2_MODE - /* - * TODO(vbendeb): restore this when it is defined how the kernel space - * gets protected. - */ - { - uint32_t perms, uid; - - RETURN_ON_FAILURE(TlclGetPermissions(KERNEL_NV_INDEX, &perms)); - memcpy(&uid, &rsk.uid, sizeof(uid)); - if (TPM_NV_PER_PPWRITE != perms || - ROLLBACK_SPACE_KERNEL_UID != uid) - return TPM_E_CORRUPTED_STATE; - } -#endif memcpy(version, &rsk.kernel_versions, sizeof(*version)); VB2_DEBUG("TPM: RollbackKernelRead 0x%x\n", (int)*version); return TPM_SUCCESS; |