[PATCH v5] tpm: Map the ACPI provided event log

Jarkko Sakkinen
2024-12-24T04:03:40Z

The following failure was reported:

[ 10.693310][ T1] tpm_tis STM0925:00: 2.0 TPM (device-id 0x3, rev-id 0)
[ 10.848132][ T1] ------------[ cut here ]------------
[ 10.853559][ T1] WARNING: CPU: 59 PID: 1 at mm/page_alloc.c:4727 __alloc_pages_noprof+0x2ca/0x330
[ 10.862827][ T1] Modules linked in:
[ 10.866671][ T1] CPU: 59 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-lp155.2.g52785e2-default #1 openSUSE Tumbleweed (unreleased) 588cd98293a7c9eba9013378d807364c088c9375
[ 10.882741][ T1] Hardware name: HPE ProLiant DL320 Gen12/ProLiant DL320 Gen12, BIOS 1.20 10/28/2024
[ 10.892170][ T1] RIP: 0010:__alloc_pages_noprof+0x2ca/0x330
[ 10.898103][ T1] Code: 24 08 e9 4a fe ff ff e8 34 36 fa ff e9 88 fe ff ff 83 fe 0a 0f 86 b3 fd ff ff 80 3d 01 e7 ce 01 00 75 09 c6 05 f8 e6 ce 01 01 <0f> 0b 45 31 ff e9 e5 fe ff ff f7 c2 00 00 08 00 75 42 89 d9 80 e1
[ 10.917750][ T1] RSP: 0000:ffffb7cf40077980 EFLAGS: 00010246
[ 10.923777][ T1] RAX: 0000000000000000 RBX: 0000000000040cc0 RCX: 0000000000000000
[ 10.931727][ T1] RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000040cc0

Above shows that ACPI pointed a 16 MiB buffer for the log events because
RSI maps to the 'order' parameter of __alloc_pages_noprof(). Address the
bug by mapping the region when needed instead of copying.

Cc: stable@vger.kernel.org # v2.6.16+
Fixes: 55a82ab3181b ("[PATCH] tpm: add bios measurement log")
Reported-by: Andy Liang <andy.liang@hpe.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219495
Suggested-by: Matthew Garrett <mjg59@srcf.ucam.org>
Tested-by: Andy Liang <andy.liang@hpe.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
---
v5:
* Spotted this right after sending: remove extra acpi_os_unmap_iomem()
call.
v4:
* Added tested-by from Andy Liang.
v3:
* Flag mapping code in tpm{1,2}.c with CONFIG_ACPI (nios2 compilation
fix).
v2:
* There was some extra cruft (irrelevant diff), which is now wiped away.
* Added missing tags (fixes, stable).
---
drivers/char/tpm/eventlog/acpi.c | 27 ++++++---------------
drivers/char/tpm/eventlog/common.c | 25 +++++++++++++-------
drivers/char/tpm/eventlog/common.h | 28 ++++++++++++++++++++++
drivers/char/tpm/eventlog/tpm1.c | 30 ++++++++++++++---------
drivers/char/tpm/eventlog/tpm2.c | 38 +++++++++++++++++-------------
include/linux/tpm.h | 1 +
6 files changed, 94 insertions(+), 55 deletions(-)

diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
index 69533d0bfb51..fb84dd3f6106 100644
--- a/drivers/char/tpm/eventlog/acpi.c
+++ b/drivers/char/tpm/eventlog/acpi.c
@@ -70,14 +70,11 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
acpi_status status;
void __iomem *virt;
u64 len, start;
- struct tpm_bios_log *log;
struct acpi_table_tpm2 *tbl;
struct acpi_tpm2_phy *tpm2_phy;
int format;
int ret;

- log = &chip->log;
-
/* Unfortuntely ACPI does not associate the event log with a specific
* TPM, like PPI. Thus all ACPI TPMs will read the same log.
*/
@@ -135,36 +132,26 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
return -EIO;
}

- /* malloc EventLog space */
- log->bios_event_log = devm_kmalloc(&chip->dev, len, GFP_KERNEL);
- if (!log->bios_event_log)
- return -ENOMEM;
-
- log->bios_event_log_end = log->bios_event_log + len;
-
virt = acpi_os_map_iomem(start, len);
if (!virt) {
dev_warn(&chip->dev, "%s: Failed to map ACPI memory\n", __func__);
/* try EFI log next */
- ret = -ENODEV;
- goto err;
+ return -ENODEV;
}

- memcpy_fromio(log->bios_event_log, virt, len);
-
- acpi_os_unmap_iomem(virt, len);
-
- if (chip->flags & TPM_CHIP_FLAG_TPM2 &&
- !tpm_is_tpm2_log(log->bios_event_log, len)) {
+ if (chip->flags & TPM_CHIP_FLAG_TPM2 && !tpm_is_tpm2_log(virt, len)) {
/* try EFI log next */
ret = -ENODEV;
goto err;
}

+ acpi_os_unmap_iomem(virt, len);
+ chip->flags |= TPM_CHIP_FLAG_ACPI_LOG;
+ chip->log.bios_event_log = (void *)start;
+ chip->log.bios_event_log_end = (void *)start + len;
return format;

err:
- devm_kfree(&chip->dev, log->bios_event_log);
- log->bios_event_log = NULL;
+ acpi_os_unmap_iomem(virt, len);
return ret;
}
diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
index 4c0bbba64ee5..44340ca6e2ac 100644
--- a/drivers/char/tpm/eventlog/common.c
+++ b/drivers/char/tpm/eventlog/common.c
@@ -27,6 +27,7 @@ static int tpm_bios_measurements_open(struct inode *inode,
{
int err;
struct seq_file *seq;
+ struct tpm_measurements *priv;
struct tpm_chip_seqops *chip_seqops;
const struct seq_operations *seqops;
struct tpm_chip *chip;
@@ -42,13 +43,18 @@ static int tpm_bios_measurements_open(struct inode *inode,
get_device(&chip->dev);
inode_unlock(inode);

- /* now register seq file */
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->chip = chip;
+
err = seq_open(file, seqops);
- if (!err) {
- seq = file->private_data;
- seq->private = chip;
- } else {
+ if (err) {
+ kfree(priv);
put_device(&chip->dev);
+ } else {
+ seq = file->private_data;
+ seq->private = priv;
}

return err;
@@ -58,11 +64,14 @@ static int tpm_bios_measurements_release(struct inode *inode,
struct file *file)
{
struct seq_file *seq = file->private_data;
- struct tpm_chip *chip = seq->private;
+ struct tpm_measurements *priv = seq->private;
+ int ret;

- put_device(&chip->dev);
+ put_device(&priv->chip->dev);
+ ret = seq_release(inode, file);
+ kfree(priv);

- return seq_release(inode, file);
+ return ret;
}

static const struct file_operations tpm_bios_measurements_ops = {
diff --git a/drivers/char/tpm/eventlog/common.h b/drivers/char/tpm/eventlog/common.h
index 47ff8136ceb5..b98fd6d9a6e9 100644
--- a/drivers/char/tpm/eventlog/common.h
+++ b/drivers/char/tpm/eventlog/common.h
@@ -1,12 +1,40 @@
#ifndef __TPM_EVENTLOG_COMMON_H__
#define __TPM_EVENTLOG_COMMON_H__

+#include <linux/acpi.h>
#include "../tpm.h"

extern const struct seq_operations tpm1_ascii_b_measurements_seqops;
extern const struct seq_operations tpm1_binary_b_measurements_seqops;
extern const struct seq_operations tpm2_binary_b_measurements_seqops;

+struct tpm_measurements {
+ struct tpm_chip *chip;
+ void *start;
+ void *end;
+};
+
+static inline bool tpm_measurements_map(struct tpm_measurements *measurements)
+{
+ struct tpm_chip *chip = measurements->chip;
+ struct tpm_bios_log *log = &chip->log;
+ size_t size;
+
+ size = log->bios_event_log_end - log->bios_event_log;
+ measurements->start = log->bios_event_log;
+
+#ifdef CONFIG_ACPI
+ if (chip->flags & TPM_CHIP_FLAG_ACPI_LOG)
+ measurements->start = acpi_os_map_iomem((unsigned long)log->bios_event_log, size);
+#endif
+
+ if (!measurements->start)
+ return false;
+
+ measurements->end = measurements->start + size;
+ return true;
+}
+
#if defined(CONFIG_ACPI)
int tpm_read_log_acpi(struct tpm_chip *chip);
#else
diff --git a/drivers/char/tpm/eventlog/tpm1.c b/drivers/char/tpm/eventlog/tpm1.c
index 12ee42a31c71..aef6ee39423a 100644
--- a/drivers/char/tpm/eventlog/tpm1.c
+++ b/drivers/char/tpm/eventlog/tpm1.c
@@ -70,20 +70,23 @@ static const char* tcpa_pc_event_id_strings[] = {
static void *tpm1_bios_measurements_start(struct seq_file *m, loff_t *pos)
{
loff_t i = 0;
- struct tpm_chip *chip = m->private;
- struct tpm_bios_log *log = &chip->log;
- void *addr = log->bios_event_log;
- void *limit = log->bios_event_log_end;
+ struct tpm_measurements *priv = m->private;
struct tcpa_event *event;
u32 converted_event_size;
u32 converted_event_type;
+ void *addr;
+
+ if (!tpm_measurements_map(priv))
+ return NULL;
+
+ addr = priv->start;

/* read over *pos measurements */
do {
event = addr;

/* check if current entry is valid */
- if (addr + sizeof(struct tcpa_event) > limit)
+ if (addr + sizeof(struct tcpa_event) > priv->end)
return NULL;

converted_event_size =
@@ -93,7 +96,7 @@ static void *tpm1_bios_measurements_start(struct seq_file *m, loff_t *pos)

if (((converted_event_type == 0) && (converted_event_size == 0))
|| ((addr + sizeof(struct tcpa_event) + converted_event_size)
- > limit))
+ > priv->end))
return NULL;

if (i++ == *pos)
@@ -109,9 +112,7 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v,
loff_t *pos)
{
struct tcpa_event *event = v;
- struct tpm_chip *chip = m->private;
- struct tpm_bios_log *log = &chip->log;
- void *limit = log->bios_event_log_end;
+ struct tpm_measurements *priv = m->private;
u32 converted_event_size;
u32 converted_event_type;

@@ -121,7 +122,7 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v,
v += sizeof(struct tcpa_event) + converted_event_size;

/* now check if current entry is valid */
- if ((v + sizeof(struct tcpa_event)) > limit)
+ if ((v + sizeof(struct tcpa_event)) > priv->end)
return NULL;

event = v;
@@ -130,7 +131,7 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v,
converted_event_type = do_endian_conversion(event->event_type);

if (((converted_event_type == 0) && (converted_event_size == 0)) ||
- ((v + sizeof(struct tcpa_event) + converted_event_size) > limit))
+ ((v + sizeof(struct tcpa_event) + converted_event_size) > priv->end))
return NULL;

return v;
@@ -138,6 +139,13 @@ static void *tpm1_bios_measurements_next(struct seq_file *m, void *v,

static void tpm1_bios_measurements_stop(struct seq_file *m, void *v)
{
+#ifdef CONFIG_ACPI
+ struct tpm_measurements *priv = m->private;
+ struct tpm_chip *chip = priv->chip;
+
+ if (chip->flags & TPM_CHIP_FLAG_ACPI_LOG)
+ acpi_os_unmap_iomem(priv->start, priv->end - priv->start);
+#endif
}

static int get_event_name(char *dest, struct tcpa_event *event,
diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c
index 37a05800980c..6289d8893e46 100644
--- a/drivers/char/tpm/eventlog/tpm2.c
+++ b/drivers/char/tpm/eventlog/tpm2.c
@@ -41,20 +41,22 @@ static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event,

static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
{
- struct tpm_chip *chip = m->private;
- struct tpm_bios_log *log = &chip->log;
- void *addr = log->bios_event_log;
- void *limit = log->bios_event_log_end;
+ struct tpm_measurements *priv = m->private;
struct tcg_pcr_event *event_header;
struct tcg_pcr_event2_head *event;
size_t size;
+ void *addr;
int i;

+ if (!tpm_measurements_map(priv))
+ return NULL;
+
+ addr = priv->start;
event_header = addr;
size = struct_size(event_header, event, event_header->event_size);

if (*pos == 0) {
- if (addr + size < limit) {
+ if (addr + size < priv->end) {
if ((event_header->event_type == 0) &&
(event_header->event_size == 0))
return NULL;
@@ -66,7 +68,7 @@ static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
addr += size;
event = addr;
size = calc_tpm2_event_size(event, event_header);
- if ((addr + size >= limit) || (size == 0))
+ if ((addr + size >= priv->end) || !size)
return NULL;
}

@@ -74,7 +76,7 @@ static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos)
event = addr;
size = calc_tpm2_event_size(event, event_header);

- if ((addr + size >= limit) || (size == 0))
+ if ((addr + size >= priv->end) || !size)
return NULL;
addr += size;
}
@@ -87,14 +89,12 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
{
struct tcg_pcr_event *event_header;
struct tcg_pcr_event2_head *event;
- struct tpm_chip *chip = m->private;
- struct tpm_bios_log *log = &chip->log;
- void *limit = log->bios_event_log_end;
+ struct tpm_measurements *priv = m->private;
size_t event_size;
void *marker;

(*pos)++;
- event_header = log->bios_event_log;
+ event_header = priv->start;

if (v == SEQ_START_TOKEN) {
event_size = struct_size(event_header, event,
@@ -109,13 +109,13 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,
}

marker = marker + event_size;
- if (marker >= limit)
+ if (marker >= priv->end)
return NULL;
v = marker;
event = v;

event_size = calc_tpm2_event_size(event, event_header);
- if (((v + event_size) >= limit) || (event_size == 0))
+ if (((v + event_size) >= priv->end) || !event_size)
return NULL;

return v;
@@ -123,13 +123,19 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v,

static void tpm2_bios_measurements_stop(struct seq_file *m, void *v)
{
+#ifdef CONFIG_ACPI
+ struct tpm_measurements *priv = m->private;
+ struct tpm_chip *chip = priv->chip;
+
+ if (chip->flags & TPM_CHIP_FLAG_ACPI_LOG)
+ acpi_os_unmap_iomem(priv->start, priv->end - priv->start);
+#endif
}

static int tpm2_binary_bios_measurements_show(struct seq_file *m, void *v)
{
- struct tpm_chip *chip = m->private;
- struct tpm_bios_log *log = &chip->log;
- struct tcg_pcr_event *event_header = log->bios_event_log;
+ struct tpm_measurements *priv = m->private;
+ struct tcg_pcr_event *event_header = priv->start;
struct tcg_pcr_event2_head *event = v;
void *temp_ptr;
size_t size;
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 20a40ade8030..f3d12738b93b 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -348,6 +348,7 @@ enum tpm_chip_flags {
TPM_CHIP_FLAG_SUSPENDED = BIT(8),
TPM_CHIP_FLAG_HWRNG_DISABLED = BIT(9),
TPM_CHIP_FLAG_DISABLE = BIT(10),
+ TPM_CHIP_FLAG_ACPI_LOG = BIT(11),
};

#define to_tpm_chip(d) container_of(d, struct tpm_chip, dev)
--
2.47.1