From: Ming Lei <tom.leiming@gmail.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Maxim Patlasov <MPatlasov@parallels.com>,
Robert Baldyga <r.baldyga@samsung.com>,
Michal Nazarewicz <mina86@mina86.com>,
Felipe Balbi <balbi@ti.com>,
"open list:AIO" <linux-aio@kvack.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>,
stable <stable@vger.kernel.org>
Subject: Re: [PATCH 06/12] gadgetfs: use-after-free in ->aio_read()
Date: Sun, 8 Mar 2015 18:07:00 +0800 [thread overview]
Message-ID: <CACVXFVMZeiZML6Hxxn1sdObj-cqRO8fv9L+x9T0LuwcMd2Xsbg@mail.gmail.com> (raw)
In-Reply-To: <1424714436-19371-7-git-send-email-hch@lst.de>
On Tue, Feb 24, 2015 at 2:00 AM, Christoph Hellwig <hch@lst.de> wrote:
> From: Al Viro <viro@zeniv.linux.org.uk>
>
> AIO_PREAD requests call ->aio_read() with iovec on caller's stack, so if
> we are going to access it asynchronously, we'd better get ourselves
> a copy - the one on kernel stack of aio_run_iocb() won't be there
> anymore. function/f_fs.c take care of doing that, legacy/inode.c
> doesn't...
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
> drivers/usb/gadget/legacy/inode.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
> index db49ec4..9fbbaa0 100644
> --- a/drivers/usb/gadget/legacy/inode.c
> +++ b/drivers/usb/gadget/legacy/inode.c
> @@ -566,7 +566,6 @@ static ssize_t ep_copy_to_user(struct kiocb_priv *priv)
> if (total == 0)
> break;
> }
> -
> return len;
> }
>
> @@ -585,6 +584,7 @@ static void ep_user_copy_worker(struct work_struct *work)
> aio_complete(iocb, ret, ret);
>
> kfree(priv->buf);
> + kfree(priv->iv);
> kfree(priv);
> }
>
> @@ -605,6 +605,7 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
> */
> if (priv->iv == NULL || unlikely(req->actual == 0)) {
> kfree(req->buf);
> + kfree(priv->iv);
> kfree(priv);
> iocb->private = NULL;
> /* aio_complete() reports bytes-transferred _and_ faults */
> @@ -640,7 +641,7 @@ ep_aio_rwtail(
> struct usb_request *req;
> ssize_t value;
>
> - priv = kmalloc(sizeof *priv, GFP_KERNEL);
> + priv = kzalloc(sizeof *priv, GFP_KERNEL);
> if (!priv) {
> value = -ENOMEM;
> fail:
> @@ -649,7 +650,14 @@ fail:
> }
> iocb->private = priv;
> priv->iocb = iocb;
> - priv->iv = iv;
> + if (iv) {
> + priv->iv = kmemdup(iv, nr_segs * sizeof(struct iovec),
> + GFP_KERNEL);
> + if (!priv->iv) {
> + kfree(priv);
> + goto fail;
> + }
> + }
It should be simpler and more efficient to allocate 'iv' piggyback
inside 'priv'.
> priv->nr_segs = nr_segs;
> INIT_WORK(&priv->work, ep_user_copy_worker);
>
> @@ -689,6 +697,7 @@ fail:
> mutex_unlock(&epdata->lock);
>
> if (unlikely(value)) {
> + kfree(priv->iv);
> kfree(priv);
> put_ep(epdata);
> } else
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
Thanks,
Ming Lei
next prev parent reply other threads:[~2015-03-08 10:07 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-23 18:00 [RFC] split struct kiocb Christoph Hellwig
2015-02-23 18:00 ` [PATCH 01/12] new helper: dup_iter() Christoph Hellwig
2015-02-23 18:00 ` [PATCH 02/12] move iov_iter.c from mm/ to lib/ Christoph Hellwig
2015-02-23 18:00 ` [PATCH 03/12] gadget/function/f_fs.c: close leaks Christoph Hellwig
2015-02-23 18:00 ` [PATCH 04/12] gadget/function/f_fs.c: use put iov_iter into io_data Christoph Hellwig
2015-02-23 18:00 ` [PATCH 05/12] gadget/function/f_fs.c: switch to ->{read,write}_iter() Christoph Hellwig
2015-02-23 18:00 ` [PATCH 06/12] gadgetfs: use-after-free in ->aio_read() Christoph Hellwig
2015-03-08 10:07 ` Ming Lei [this message]
2015-03-09 15:18 ` Michal Nazarewicz
2015-02-23 18:00 ` [PATCH 07/12] gadget: switch ep_io_operations to ->read_iter/->write_iter Christoph Hellwig
2015-02-23 18:00 ` [PATCH 08/12] fs: remove ki_nbytes Christoph Hellwig
2015-02-23 18:00 ` [PATCH 09/12] fuse: handle synchronous iocbs internally Christoph Hellwig
2015-03-06 2:54 ` Maxim Patlasov
2015-02-23 18:00 ` [PATCH 10/12] fs: don't allow to complete sync iocbs through aio_complete Christoph Hellwig
2015-02-23 18:00 ` [PATCH 11/12] fs: split generic and aio kiocb Christoph Hellwig
2015-02-23 18:00 ` [PATCH 12/12] fs: move struct kiocb to fs.h Christoph Hellwig
2015-02-23 21:20 ` [RFC] split struct kiocb Al Viro
2015-02-23 21:22 ` Christoph Hellwig
2015-02-23 21:39 ` Al Viro
2015-02-24 3:47 ` Al Viro
2015-02-23 21:23 ` Felipe Balbi
2015-02-23 21:42 ` Al Viro
2015-02-23 21:50 ` Felipe Balbi
2015-02-25 17:13 ` Felipe Balbi
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=CACVXFVMZeiZML6Hxxn1sdObj-cqRO8fv9L+x9T0LuwcMd2Xsbg@mail.gmail.com \
--to=tom.leiming@gmail.com \
--cc=MPatlasov@parallels.com \
--cc=balbi@ti.com \
--cc=hch@lst.de \
--cc=linux-aio@kvack.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=mina86@mina86.com \
--cc=r.baldyga@samsung.com \
--cc=stable@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/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).