diff options
| author | Johan Hovold <johan@kernel.org> | 2021-10-08 12:25:45 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-11 07:42:18 +0200 |
| commit | 880de403777376e50bdf60def359fa50a722006f (patch) | |
| tree | c92062b33c2b03023f14b9a2f5de5da228c0eda8 /drivers/usb/host | |
| parent | 5255660b208aebfdb71d574f3952cf48392f4306 (diff) | |
USB: xhci: dbc: fix tty registration race
Make sure to allocate resources before registering the tty device to
avoid having a racing open() and write() fail to enable rx or
dereference a NULL pointer when accessing the uninitialised fifo.
Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver")
Cc: stable@vger.kernel.org # 4.16
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211008092547.3996295-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host')
| -rw-r--r-- | drivers/usb/host/xhci-dbgtty.c | 28 |
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c index 6e784f2fc26d..eb46e642e87a 100644 --- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -408,40 +408,38 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc) return -EBUSY; xhci_dbc_tty_init_port(dbc, port); - tty_dev = tty_port_register_device(&port->port, - dbc_tty_driver, 0, NULL); - if (IS_ERR(tty_dev)) { - ret = PTR_ERR(tty_dev); - goto register_fail; - } ret = kfifo_alloc(&port->write_fifo, DBC_WRITE_BUF_SIZE, GFP_KERNEL); if (ret) - goto buf_alloc_fail; + goto err_exit_port; ret = xhci_dbc_alloc_requests(dbc, BULK_IN, &port->read_pool, dbc_read_complete); if (ret) - goto request_fail; + goto err_free_fifo; ret = xhci_dbc_alloc_requests(dbc, BULK_OUT, &port->write_pool, dbc_write_complete); if (ret) - goto request_fail; + goto err_free_requests; + + tty_dev = tty_port_register_device(&port->port, + dbc_tty_driver, 0, NULL); + if (IS_ERR(tty_dev)) { + ret = PTR_ERR(tty_dev); + goto err_free_requests; + } port->registered = true; return 0; -request_fail: +err_free_requests: xhci_dbc_free_requests(&port->read_pool); xhci_dbc_free_requests(&port->write_pool); +err_free_fifo: kfifo_free(&port->write_fifo); - -buf_alloc_fail: - tty_unregister_device(dbc_tty_driver, 0); - -register_fail: +err_exit_port: xhci_dbc_tty_exit_port(port); dev_err(dbc->dev, "can't register tty port, err %d\n", ret); |