From: Tadeusz Struk <tadeusz.struk@intel.com>
To: jarkko.sakkinen@linux.intel.com
Cc: tadeusz.struk@intel.com, peterz@infradead.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
jgg@ziepe.ca, mingo@redhat.com, jeffrin@rajagiritech.edu.in,
linux-integrity@vger.kernel.org, will@kernel.org,
peterhuewe@gmx.de
Subject: [PATCH] tpm: fix WARNING: lock held when returning to user space
Date: Tue, 10 Dec 2019 13:17:51 -0800 [thread overview]
Message-ID: <157601267151.12904.7408818232910113434.stgit@tstruk-mobl1> (raw)
In-Reply-To: <34e5340f-de75-f20e-7898-6142eac45c13@intel.com>
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 silence this warning the driver needs to release the mutex
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)
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
---
drivers/char/tpm/tpm-dev-common.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c
index 2ec47a69a2a6..b23b0b999232 100644
--- a/drivers/char/tpm/tpm-dev-common.c
+++ b/drivers/char/tpm/tpm-dev-common.c
@@ -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;
}
next prev parent reply other threads:[~2019-12-10 21:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-07 17:34 [PROBLEM]: WARNING: lock held when returning to user space! (5.4.1 #16 Tainted: G ) Jeffrin Jose
2019-12-09 10:34 ` Will Deacon
2019-12-09 20:25 ` Jarkko Sakkinen
2019-12-09 21:34 ` Tadeusz Struk
2019-12-10 19:04 ` [PATCH] tpm: selftest: add test covering async mode Tadeusz Struk
2019-12-11 17:42 ` Jarkko Sakkinen
2019-12-10 21:17 ` Tadeusz Struk [this message]
2019-12-11 17:47 ` [PATCH] tpm: fix WARNING: lock held when returning to user space Jarkko Sakkinen
2019-12-11 17:52 ` Jarkko Sakkinen
2019-12-11 18:00 ` Jarkko Sakkinen
2019-12-11 15:17 ` [PROBLEM]: WARNING: lock held when returning to user space! (5.4.1 #16 Tainted: G ) Jeffrin Jose
2019-12-11 18:36 ` Tadeusz Struk
2019-12-12 8:12 ` Jeffrin Jose
2019-12-11 17:45 ` Jarkko Sakkinen
2019-12-11 18:18 ` Jeffrin Jose
2019-12-11 18:22 ` Jeffrin Jose
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=157601267151.12904.7408818232910113434.stgit@tstruk-mobl1 \
--to=tadeusz.struk@intel.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jeffrin@rajagiritech.edu.in \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterhuewe@gmx.de \
--cc=peterz@infradead.org \
--cc=stable@vger.kernel.org \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).