From: jgunthorpe@obsidianresearch.com (Jason Gunthorpe)
To: linux-arm-kernel@lists.infradead.org
Subject: [tpmdd-devel] [RFC PATCH 1/2] tee: generic TEE subsystem
Date: Fri, 17 Apr 2015 10:30:54 -0600 [thread overview]
Message-ID: <20150417163054.GA28241@obsidianresearch.com> (raw)
In-Reply-To: <1429257057-7935-2-git-send-email-jens.wiklander@linaro.org>
On Fri, Apr 17, 2015 at 09:50:56AM +0200, Jens Wiklander wrote:
> + teedev = devm_kzalloc(dev, sizeof(*teedev), GFP_KERNEL);
[..]
> + rc = misc_register(&teedev->miscdev);
[..]
> +void tee_unregister(struct tee_device *teedev)
> +{
[..]
> + misc_deregister(&teedev->miscdev);
> +}
[..]
>+static int optee_remove(struct platform_device *pdev)
>+{
>+ tee_unregister(optee->teedev);
Isn't that a potential use after free? AFAIK misc_deregister does not
guarentee the miscdev will no longer be accessed after it returns, and
the devm will free it after optee_remove returns.
Memory backing a stuct device needs to be freed via the release
function.
We have been going through this for a while with TPM - it seems like
using misc devices dynamically is not a good idea. Manage your own
struct device directly..
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: Jens Wiklander <jens.wiklander@linaro.org>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
javier@javigon.com, valentin.manea@huawei.com,
emmanuel.michel@st.com, Herbert Xu <herbert@gondor.apana.org.au>,
jean-michel.delorme@st.com, tpmdd-devel@lists.sourceforge.net
Subject: Re: [tpmdd-devel] [RFC PATCH 1/2] tee: generic TEE subsystem
Date: Fri, 17 Apr 2015 10:30:54 -0600 [thread overview]
Message-ID: <20150417163054.GA28241@obsidianresearch.com> (raw)
In-Reply-To: <1429257057-7935-2-git-send-email-jens.wiklander@linaro.org>
On Fri, Apr 17, 2015 at 09:50:56AM +0200, Jens Wiklander wrote:
> + teedev = devm_kzalloc(dev, sizeof(*teedev), GFP_KERNEL);
[..]
> + rc = misc_register(&teedev->miscdev);
[..]
> +void tee_unregister(struct tee_device *teedev)
> +{
[..]
> + misc_deregister(&teedev->miscdev);
> +}
[..]
>+static int optee_remove(struct platform_device *pdev)
>+{
>+ tee_unregister(optee->teedev);
Isn't that a potential use after free? AFAIK misc_deregister does not
guarentee the miscdev will no longer be accessed after it returns, and
the devm will free it after optee_remove returns.
Memory backing a stuct device needs to be freed via the release
function.
We have been going through this for a while with TPM - it seems like
using misc devices dynamically is not a good idea. Manage your own
struct device directly..
Jason
next prev parent reply other threads:[~2015-04-17 16:30 UTC|newest]
Thread overview: 85+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-17 7:50 [RFC PATCH 0/2] generic TEE subsystem Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-17 7:50 ` [RFC PATCH 1/2] tee: " Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-17 16:30 ` Jason Gunthorpe [this message]
2015-04-17 16:30 ` [tpmdd-devel] " Jason Gunthorpe
2015-04-18 9:01 ` Russell King - ARM Linux
2015-04-18 9:01 ` Russell King - ARM Linux
2015-04-18 9:01 ` Russell King - ARM Linux
2015-04-18 17:29 ` Jason Gunthorpe
2015-04-18 17:29 ` Jason Gunthorpe
2015-04-18 17:29 ` Jason Gunthorpe
2015-04-18 21:57 ` Russell King - ARM Linux
2015-04-18 21:57 ` Russell King - ARM Linux
2015-04-18 21:57 ` Russell King - ARM Linux
2015-04-20 5:08 ` Jason Gunthorpe
2015-04-20 5:08 ` Jason Gunthorpe
2015-04-20 14:54 ` Greg Kroah-Hartman
2015-04-20 14:54 ` Greg Kroah-Hartman
2015-04-20 15:56 ` Jason Gunthorpe
2015-04-20 15:56 ` Jason Gunthorpe
2015-04-20 15:56 ` Jason Gunthorpe
2015-04-20 16:05 ` Greg Kroah-Hartman
2015-04-20 16:05 ` Greg Kroah-Hartman
2015-04-20 16:05 ` Greg Kroah-Hartman
2015-04-20 13:02 ` Jens Wiklander
2015-04-20 13:02 ` Jens Wiklander
2015-04-20 13:02 ` Jens Wiklander
2015-04-20 17:55 ` Jason Gunthorpe
2015-04-20 17:55 ` Jason Gunthorpe
2015-04-20 17:55 ` Jason Gunthorpe
2015-04-21 5:59 ` Jens Wiklander
2015-04-21 5:59 ` Jens Wiklander
2015-04-17 20:07 ` Arnd Bergmann
2015-04-17 20:07 ` Arnd Bergmann
2015-04-18 7:20 ` Paul Bolle
2015-04-18 7:20 ` Paul Bolle
2015-04-18 7:20 ` Paul Bolle
2015-04-20 6:20 ` Jens Wiklander
2015-04-20 6:20 ` Jens Wiklander
2015-04-20 18:20 ` [tpmdd-devel] " Jason Gunthorpe
2015-04-20 18:20 ` Jason Gunthorpe
2015-04-21 10:45 ` Jens Wiklander
2015-04-21 10:45 ` Jens Wiklander
2015-04-18 8:55 ` Greg Kroah-Hartman
2015-04-18 8:55 ` Greg Kroah-Hartman
2015-04-18 8:57 ` Greg Kroah-Hartman
2015-04-18 8:57 ` Greg Kroah-Hartman
2015-04-18 9:04 ` Russell King - ARM Linux
2015-04-18 9:04 ` Russell King - ARM Linux
2015-04-18 9:04 ` Russell King - ARM Linux
2015-04-18 18:47 ` Greg Kroah-Hartman
2015-04-18 18:47 ` Greg Kroah-Hartman
2015-04-18 19:02 ` Russell King - ARM Linux
2015-04-18 19:02 ` Russell King - ARM Linux
2015-04-18 20:37 ` Greg Kroah-Hartman
2015-04-18 20:37 ` Greg Kroah-Hartman
2015-04-18 20:50 ` Russell King - ARM Linux
2015-04-18 20:50 ` Russell King - ARM Linux
2015-04-19 7:00 ` Greg Kroah-Hartman
2015-04-19 7:00 ` Greg Kroah-Hartman
2015-04-17 7:50 ` [RFC PATCH 2/2] tee: add OP-TEE driver Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-17 7:50 ` Jens Wiklander
2015-04-18 8:57 ` Greg Kroah-Hartman
2015-04-18 8:57 ` Greg Kroah-Hartman
2015-04-18 9:36 ` Javier González
2015-04-18 9:36 ` Javier González
2015-04-18 9:36 ` Javier González
2015-04-18 18:49 ` Greg Kroah-Hartman
2015-04-18 18:49 ` Greg Kroah-Hartman
2015-04-18 19:01 ` Arnd Bergmann
2015-04-18 19:01 ` Arnd Bergmann
2015-04-19 11:17 ` Javier González
2015-04-19 11:17 ` Javier González
2015-04-19 19:47 ` Arnd Bergmann
2015-04-19 19:47 ` Arnd Bergmann
2015-04-20 7:05 ` Javier González
2015-04-20 7:05 ` Javier González
2015-04-20 7:05 ` Javier González
2015-04-20 6:42 ` Jens Wiklander
2015-04-20 6:42 ` Jens Wiklander
2015-04-20 6:42 ` Jens Wiklander
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=20150417163054.GA28241@obsidianresearch.com \
--to=jgunthorpe@obsidianresearch.com \
--cc=linux-arm-kernel@lists.infradead.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.