OpenCloudOS-Kernel/drivers/firmware/efi/tpm.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017 Google, Inc.
* Thiebaud Weksteen <tweek@google.com>
*/
#define TPM_MEMREMAP(start, size) early_memremap(start, size)
#define TPM_MEMUNMAP(start, size) early_memunmap(start, size)
#include <asm/early_ioremap.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/tpm_eventlog.h>
int efi_tpm_final_log_size;
EXPORT_SYMBOL(efi_tpm_final_log_size);
static int __init tpm2_calc_event_log_size(void *data, int count, void *size_info)
{
struct tcg_pcr_event2_head *header;
int event_size, size = 0;
while (count > 0) {
header = data + size;
event_size = __calc_tpm2_event_size(header, size_info, true);
if (event_size == 0)
return -1;
size += event_size;
count--;
}
return size;
}
/*
* Reserve the memory associated with the TPM Event Log configuration table.
*/
int __init efi_tpm_eventlog_init(void)
{
struct linux_efi_tpm_eventlog *log_tbl;
struct efi_tcg2_final_events_table *final_tbl;
int tbl_size;
int ret = 0;
if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) {
/*
* We can't calculate the size of the final events without the
* first entry in the TPM log, so bail here.
*/
return 0;
}
log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl));
if (!log_tbl) {
pr_err("Failed to map TPM Event Log table @ 0x%lx\n",
efi.tpm_log);
efi.tpm_log = EFI_INVALID_TABLE_ADDR;
return -ENOMEM;
}
tbl_size = sizeof(*log_tbl) + log_tbl->size;
memblock_reserve(efi.tpm_log, tbl_size);
if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) {
pr_info("TPM Final Events table not present\n");
goto out;
} else if (log_tbl->version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) {
pr_warn(FW_BUG "TPM Final Events table invalid\n");
goto out;
}
final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl));
if (!final_tbl) {
pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n",
efi.tpm_final_log);
efi.tpm_final_log = EFI_INVALID_TABLE_ADDR;
ret = -ENOMEM;
goto out;
}
tbl_size = 0;
if (final_tbl->nr_events != 0) {
void *events = (void *)efi.tpm_final_log
+ sizeof(final_tbl->version)
+ sizeof(final_tbl->nr_events);
tbl_size = tpm2_calc_event_log_size(events,
final_tbl->nr_events,
log_tbl->log);
}
efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing If __calc_tpm2_event_size() fails to parse an event it will return 0, resulting tpm2_calc_event_log_size() returning -1. Currently there is no check of this return value, and 'efi_tpm_final_log_size' can end up being set to this negative value resulting in a crash like this one: BUG: unable to handle page fault for address: ffffbc8fc00866ad #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:memcpy_erms+0x6/0x10 Call Trace: tpm_read_log_efi() tpm_bios_log_setup() tpm_chip_register() tpm_tis_core_init.cold.9+0x28c/0x466 tpm_tis_plat_probe() platform_drv_probe() ... Also __calc_tpm2_event_size() returns a size of 0 when it fails to parse an event, so update function documentation to reflect this. The root cause of the issue that caused the failure of event parsing in this case is resolved by Peter Jone's patchset dealing with large event logs where crossing over a page boundary causes the page with the event count to be unmapped. Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Dave Young <dyoung@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Lyude Paul <lyude@redhat.com> Cc: Matthew Garrett <mjg59@google.com> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Talbert <swt@techie.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org Fixes: c46f3405692de ("tpm: Reserve the TPM final events table") Link: https://lkml.kernel.org/r/20191002165904.8819-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-03 00:59:02 +08:00
if (tbl_size < 0) {
pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
ret = -EINVAL;
efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing If __calc_tpm2_event_size() fails to parse an event it will return 0, resulting tpm2_calc_event_log_size() returning -1. Currently there is no check of this return value, and 'efi_tpm_final_log_size' can end up being set to this negative value resulting in a crash like this one: BUG: unable to handle page fault for address: ffffbc8fc00866ad #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:memcpy_erms+0x6/0x10 Call Trace: tpm_read_log_efi() tpm_bios_log_setup() tpm_chip_register() tpm_tis_core_init.cold.9+0x28c/0x466 tpm_tis_plat_probe() platform_drv_probe() ... Also __calc_tpm2_event_size() returns a size of 0 when it fails to parse an event, so update function documentation to reflect this. The root cause of the issue that caused the failure of event parsing in this case is resolved by Peter Jone's patchset dealing with large event logs where crossing over a page boundary causes the page with the event count to be unmapped. Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Dave Young <dyoung@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Lyude Paul <lyude@redhat.com> Cc: Matthew Garrett <mjg59@google.com> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Talbert <swt@techie.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org Fixes: c46f3405692de ("tpm: Reserve the TPM final events table") Link: https://lkml.kernel.org/r/20191002165904.8819-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-03 00:59:02 +08:00
goto out_calc;
}
memblock_reserve(efi.tpm_final_log,
tbl_size + sizeof(*final_tbl));
efi_tpm_final_log_size = tbl_size;
efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing If __calc_tpm2_event_size() fails to parse an event it will return 0, resulting tpm2_calc_event_log_size() returning -1. Currently there is no check of this return value, and 'efi_tpm_final_log_size' can end up being set to this negative value resulting in a crash like this one: BUG: unable to handle page fault for address: ffffbc8fc00866ad #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page RIP: 0010:memcpy_erms+0x6/0x10 Call Trace: tpm_read_log_efi() tpm_bios_log_setup() tpm_chip_register() tpm_tis_core_init.cold.9+0x28c/0x466 tpm_tis_plat_probe() platform_drv_probe() ... Also __calc_tpm2_event_size() returns a size of 0 when it fails to parse an event, so update function documentation to reflect this. The root cause of the issue that caused the failure of event parsing in this case is resolved by Peter Jone's patchset dealing with large event logs where crossing over a page boundary causes the page with the event count to be unmapped. Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Dave Young <dyoung@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Lyude Paul <lyude@redhat.com> Cc: Matthew Garrett <mjg59@google.com> Cc: Octavian Purdila <octavian.purdila@intel.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott Talbert <swt@techie.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Cc: linux-integrity@vger.kernel.org Cc: stable@vger.kernel.org Fixes: c46f3405692de ("tpm: Reserve the TPM final events table") Link: https://lkml.kernel.org/r/20191002165904.8819-6-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-03 00:59:02 +08:00
out_calc:
early_memunmap(final_tbl, sizeof(*final_tbl));
out:
early_memunmap(log_tbl, sizeof(*log_tbl));
return ret;
}