diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2015-02-06 02:07:45 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-02-17 22:23:32 -0500 |
| commit | f01d35a15fa04162a58b95970fc01fa70ec9dacd (patch) | |
| tree | 4a54918fe9e942e5826d6e4ddfcda6bc979af21e /drivers/usb/gadget/legacy | |
| parent | 70e60d917e91fff2237095b8950810effa2b1a50 (diff) | |
gadgetfs: use-after-free in ->aio_read()
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>
Diffstat (limited to 'drivers/usb/gadget/legacy')
| -rw-r--r-- | drivers/usb/gadget/legacy/inode.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index db49ec4c748e..9fbbaa041a31 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 |