android/android_kernel_asus_sm8350
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tpm: fix invalid locking in NONBLOCKING mode

Browse Source 
commit d23d12484307b40eea549b8a858f5fffad913897 upstream.

When an application sends TPM commands in NONBLOCKING mode
the driver holds chip->tpm_mutex returning from write(),
which triggers: "WARNING: lock held when returning to user space".
To fix this issue the driver needs to release the mutex before
returning and acquire it again in tpm_dev_async_work() before
sending the command.

Cc: stable@vger.kernel.org
Fixes: 9e1b74a63f776 (tpm: add support for nonblocking operation)
Reported-by: Jeffrin Jose T <jeffrin@rajagiritech.edu.in>
Tested-by: Jeffrin Jose T <jeffrin@rajagiritech.edu.in>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tadeusz Struk
2019-12-12 09:48:47 -08:00
committed by Greg Kroah-Hartman
parent fed4697a04
commit 4d6ebc4c49
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/char/tpm/tpm-dev-common.c
View File

@ -61,6 +61,12 @@ static void tpm_dev_async_work(struct work_struct *work)
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);
@ -68,6 +74,7 @@ static void tpm_dev_async_work(struct work_struct *work)
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);
}
@ -204,6 +211,7 @@ ssize_t tpm_common_write(struct file *file, const char __user *buf,
if (file->f_flags & O_NONBLOCK) {
priv->command_enqueued = true;
queue_work(tpm_dev_wq, &priv->async_work);
tpm_put_ops(priv->chip);
mutex_unlock(&priv->buffer_mutex);
return size;
}