From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Maxim Patlasov <MPatlasov@parallels.com>,
Robert Baldyga <r.baldyga@samsung.com>,
Michal Nazarewicz <mina86@mina86.com>,
Felipe Balbi <balbi@ti.com>,
linux-aio@kvack.org, linux-fsdevel@vger.kernel.org,
stable@vger.kernel.org
Subject: [PATCH 06/12] gadgetfs: use-after-free in ->aio_read()
Date: Mon, 23 Feb 2015 10:00:30 -0800 [thread overview]
Message-ID: <1424714436-19371-7-git-send-email-hch@lst.de> (raw)
In-Reply-To: <1424714436-19371-1-git-send-email-hch@lst.de>
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;
+ }
+ }
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
next prev parent reply other threads:[~2015-02-23 18:02 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 ` Christoph Hellwig [this message]
2015-03-08 10:07 ` [PATCH 06/12] gadgetfs: use-after-free in ->aio_read() Ming Lei
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
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