mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Tadeusz Struk](/assets/img/avatar_default.png)
When an invalid (non existing) handle is used in a TPM command,
that uses the resource manager interface (/dev/tpmrm0) the resource
manager tries to load it from its internal cache, but fails and
the tpm_dev_transmit returns an -EINVAL error to the caller.
The existing async handler doesn't handle these error cases
currently and the condition in the poll handler never returns
mask with EPOLLIN set.
The result is that the poll call blocks and the application gets stuck
until the user_read_timer wakes it up after 120 sec.
Change the tpm_dev_async_work function to handle error conditions
returned from tpm_dev_transmit they are also reflected in the poll mask
and a correct error code could passed back to the caller.
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: <linux-integrity@vger.kernel.org>
Cc: <stable@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Fixes: 9e1b74a63f
("tpm: add support for nonblocking operation")
Tested-by: Jarkko Sakkinen<jarkko@kernel.org>
Signed-off-by: Tadeusz Struk <tstruk@gmail.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
284 lines
6.8 KiB
C
284 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2004 IBM Corporation
|
|
* Authors:
|
|
* Leendert van Doorn <leendert@watson.ibm.com>
|
|
* Dave Safford <safford@watson.ibm.com>
|
|
* Reiner Sailer <sailer@watson.ibm.com>
|
|
* Kylene Hall <kjhall@us.ibm.com>
|
|
*
|
|
* Copyright (C) 2013 Obsidian Research Corp
|
|
* Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
|
|
*
|
|
* Device file system interface to the TPM
|
|
*/
|
|
#include <linux/poll.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/workqueue.h>
|
|
#include "tpm.h"
|
|
#include "tpm-dev.h"
|
|
|
|
static struct workqueue_struct *tpm_dev_wq;
|
|
|
|
static ssize_t tpm_dev_transmit(struct tpm_chip *chip, struct tpm_space *space,
|
|
u8 *buf, size_t bufsiz)
|
|
{
|
|
struct tpm_header *header = (void *)buf;
|
|
ssize_t ret, len;
|
|
|
|
ret = tpm2_prepare_space(chip, space, buf, bufsiz);
|
|
/* If the command is not implemented by the TPM, synthesize a
|
|
* response with a TPM2_RC_COMMAND_CODE return for user-space.
|
|
*/
|
|
if (ret == -EOPNOTSUPP) {
|
|
header->length = cpu_to_be32(sizeof(*header));
|
|
header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
|
|
header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
|
|
TSS2_RESMGR_TPM_RC_LAYER);
|
|
ret = sizeof(*header);
|
|
}
|
|
if (ret)
|
|
goto out_rc;
|
|
|
|
len = tpm_transmit(chip, buf, bufsiz);
|
|
if (len < 0)
|
|
ret = len;
|
|
|
|
if (!ret)
|
|
ret = tpm2_commit_space(chip, space, buf, &len);
|
|
|
|
out_rc:
|
|
return ret ? ret : len;
|
|
}
|
|
|
|
static void tpm_dev_async_work(struct work_struct *work)
|
|
{
|
|
struct file_priv *priv =
|
|
container_of(work, struct file_priv, async_work);
|
|
ssize_t ret;
|
|
|
|
mutex_lock(&priv->buffer_mutex);
|
|
priv->command_enqueued = false;
|
|
ret = tpm_try_get_ops(priv->chip);
|
|
if (ret) {
|
|
priv->response_length = ret;
|
|
goto out;
|
|
}
|
|
|
|
ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
|
|
sizeof(priv->data_buffer));
|
|
tpm_put_ops(priv->chip);
|
|
|
|
/*
|
|
* If ret is > 0 then tpm_dev_transmit returned the size of the
|
|
* response. If ret is < 0 then tpm_dev_transmit failed and
|
|
* returned an error code.
|
|
*/
|
|
if (ret != 0) {
|
|
priv->response_length = ret;
|
|
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
|
|
}
|
|
out:
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
wake_up_interruptible(&priv->async_wait);
|
|
}
|
|
|
|
static void user_reader_timeout(struct timer_list *t)
|
|
{
|
|
struct file_priv *priv = from_timer(priv, t, user_read_timer);
|
|
|
|
pr_warn("TPM user space timeout is deprecated (pid=%d)\n",
|
|
task_tgid_nr(current));
|
|
|
|
schedule_work(&priv->timeout_work);
|
|
}
|
|
|
|
static void tpm_timeout_work(struct work_struct *work)
|
|
{
|
|
struct file_priv *priv = container_of(work, struct file_priv,
|
|
timeout_work);
|
|
|
|
mutex_lock(&priv->buffer_mutex);
|
|
priv->response_read = true;
|
|
priv->response_length = 0;
|
|
memset(priv->data_buffer, 0, sizeof(priv->data_buffer));
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
wake_up_interruptible(&priv->async_wait);
|
|
}
|
|
|
|
void tpm_common_open(struct file *file, struct tpm_chip *chip,
|
|
struct file_priv *priv, struct tpm_space *space)
|
|
{
|
|
priv->chip = chip;
|
|
priv->space = space;
|
|
priv->response_read = true;
|
|
|
|
mutex_init(&priv->buffer_mutex);
|
|
timer_setup(&priv->user_read_timer, user_reader_timeout, 0);
|
|
INIT_WORK(&priv->timeout_work, tpm_timeout_work);
|
|
INIT_WORK(&priv->async_work, tpm_dev_async_work);
|
|
init_waitqueue_head(&priv->async_wait);
|
|
file->private_data = priv;
|
|
}
|
|
|
|
ssize_t tpm_common_read(struct file *file, char __user *buf,
|
|
size_t size, loff_t *off)
|
|
{
|
|
struct file_priv *priv = file->private_data;
|
|
ssize_t ret_size = 0;
|
|
int rc;
|
|
|
|
mutex_lock(&priv->buffer_mutex);
|
|
|
|
if (priv->response_length) {
|
|
priv->response_read = true;
|
|
|
|
ret_size = min_t(ssize_t, size, priv->response_length);
|
|
if (ret_size <= 0) {
|
|
priv->response_length = 0;
|
|
goto out;
|
|
}
|
|
|
|
rc = copy_to_user(buf, priv->data_buffer + *off, ret_size);
|
|
if (rc) {
|
|
memset(priv->data_buffer, 0, TPM_BUFSIZE);
|
|
priv->response_length = 0;
|
|
ret_size = -EFAULT;
|
|
} else {
|
|
memset(priv->data_buffer + *off, 0, ret_size);
|
|
priv->response_length -= ret_size;
|
|
*off += ret_size;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (!priv->response_length) {
|
|
*off = 0;
|
|
del_singleshot_timer_sync(&priv->user_read_timer);
|
|
flush_work(&priv->timeout_work);
|
|
}
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
return ret_size;
|
|
}
|
|
|
|
ssize_t tpm_common_write(struct file *file, const char __user *buf,
|
|
size_t size, loff_t *off)
|
|
{
|
|
struct file_priv *priv = file->private_data;
|
|
int ret = 0;
|
|
|
|
if (size > TPM_BUFSIZE)
|
|
return -E2BIG;
|
|
|
|
mutex_lock(&priv->buffer_mutex);
|
|
|
|
/* Cannot perform a write until the read has cleared either via
|
|
* tpm_read or a user_read_timer timeout. This also prevents split
|
|
* buffered writes from blocking here.
|
|
*/
|
|
if ((!priv->response_read && priv->response_length) ||
|
|
priv->command_enqueued) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
if (copy_from_user(priv->data_buffer, buf, size)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
if (size < 6 ||
|
|
size < be32_to_cpu(*((__be32 *)(priv->data_buffer + 2)))) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
priv->response_length = 0;
|
|
priv->response_read = false;
|
|
*off = 0;
|
|
|
|
/*
|
|
* If in nonblocking mode schedule an async job to send
|
|
* the command return the size.
|
|
* In case of error the err code will be returned in
|
|
* the subsequent read call.
|
|
*/
|
|
if (file->f_flags & O_NONBLOCK) {
|
|
priv->command_enqueued = true;
|
|
queue_work(tpm_dev_wq, &priv->async_work);
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
return size;
|
|
}
|
|
|
|
/* atomic tpm command send and result receive. We only hold the ops
|
|
* lock during this period so that the tpm can be unregistered even if
|
|
* the char dev is held open.
|
|
*/
|
|
if (tpm_try_get_ops(priv->chip)) {
|
|
ret = -EPIPE;
|
|
goto out;
|
|
}
|
|
|
|
ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
|
|
sizeof(priv->data_buffer));
|
|
tpm_put_ops(priv->chip);
|
|
|
|
if (ret > 0) {
|
|
priv->response_length = ret;
|
|
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
|
|
ret = size;
|
|
}
|
|
out:
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
return ret;
|
|
}
|
|
|
|
__poll_t tpm_common_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct file_priv *priv = file->private_data;
|
|
__poll_t mask = 0;
|
|
|
|
poll_wait(file, &priv->async_wait, wait);
|
|
mutex_lock(&priv->buffer_mutex);
|
|
|
|
/*
|
|
* The response_length indicates if there is still response
|
|
* (or part of it) to be consumed. Partial reads decrease it
|
|
* by the number of bytes read, and write resets it the zero.
|
|
*/
|
|
if (priv->response_length)
|
|
mask = EPOLLIN | EPOLLRDNORM;
|
|
else
|
|
mask = EPOLLOUT | EPOLLWRNORM;
|
|
|
|
mutex_unlock(&priv->buffer_mutex);
|
|
return mask;
|
|
}
|
|
|
|
/*
|
|
* Called on file close
|
|
*/
|
|
void tpm_common_release(struct file *file, struct file_priv *priv)
|
|
{
|
|
flush_work(&priv->async_work);
|
|
del_singleshot_timer_sync(&priv->user_read_timer);
|
|
flush_work(&priv->timeout_work);
|
|
file->private_data = NULL;
|
|
priv->response_length = 0;
|
|
}
|
|
|
|
int __init tpm_dev_common_init(void)
|
|
{
|
|
tpm_dev_wq = alloc_workqueue("tpm_dev_wq", WQ_MEM_RECLAIM, 0);
|
|
|
|
return !tpm_dev_wq ? -ENOMEM : 0;
|
|
}
|
|
|
|
void __exit tpm_dev_common_exit(void)
|
|
{
|
|
if (tpm_dev_wq) {
|
|
destroy_workqueue(tpm_dev_wq);
|
|
tpm_dev_wq = NULL;
|
|
}
|
|
}
|