diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2016-04-14 17:01:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:48:41 -0700 |
| commit | e4c7ab76586146820b394e0176f286f5a2e70cb3 (patch) | |
| tree | 494683005513eb5ebc8fdf1600381d8d15bd6ddc /drivers/usb/gadget | |
| parent | 95b9219e05dafdb76b0707e815e5314cc0cf91af (diff) | |
usb: gadget: f_fs: Fix use-after-free
commit 38740a5b87d53ceb89eb2c970150f6e94e00373a upstream.
When using asynchronous read or write operations on the USB endpoints the
issuer of the IO request is notified by calling the ki_complete() callback
of the submitted kiocb when the URB has been completed.
Calling this ki_complete() callback will free kiocb. Make sure that the
structure is no longer accessed beyond that point, otherwise undefined
behaviour might occur.
Fixes: 2e4c7553cd6f ("usb: gadget: f_fs: add aio support")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/function/f_fs.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index cf43e9e18368..79d895c2dd71 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -646,6 +646,7 @@ static void ffs_user_copy_worker(struct work_struct *work) work); int ret = io_data->req->status ? io_data->req->status : io_data->req->actual; + bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD; if (io_data->read && ret > 0) { use_mm(io_data->mm); @@ -657,13 +658,11 @@ static void ffs_user_copy_worker(struct work_struct *work) io_data->kiocb->ki_complete(io_data->kiocb, ret, ret); - if (io_data->ffs->ffs_eventfd && - !(io_data->kiocb->ki_flags & IOCB_EVENTFD)) + if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd) eventfd_signal(io_data->ffs->ffs_eventfd, 1); usb_ep_free_request(io_data->ep, io_data->req); - io_data->kiocb->private = NULL; if (io_data->read) kfree(io_data->to_free); kfree(io_data->buf); |