diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2016-04-14 17:01:17 +0200 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2016-04-20 10:38:06 +0300 |
| commit | 38740a5b87d53ceb89eb2c970150f6e94e00373a (patch) | |
| tree | 3846402f09e425009ae20f6f0f58be4227291cab | |
| parent | 9772b47a4c2916d645c551228b6085ea24acbe5d (diff) | |
usb: gadget: f_fs: Fix use-after-free
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")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
| -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 e21ca2bd6839..15b648cbc75c 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); |