diff options
authorDavid Woodhouse <>2009-05-18 13:07:35 +0100
committerLinus Torvalds <>2009-05-18 08:37:15 -0700
commit80193195f87ebca6d7417516d6edeb3969631c15 (patch)
parentdbf8c11f821b6ff83302c34f2403b4f7231f50ae (diff)
Fix oops on close of hot-unplugged FTDI serial converter
Commit c45d6320 ("fix reference counting of ftdi_private") stopped ftdi_sio_port_remove() from directly freeing the port-private data, with the intention if the port was still open, it would be freed when ftdi_close() is eventually called and releases the last refcount on the structure. That's all very well, but ftdi_sio_port_remove() still contains a call to usb_set_serial_port_data(port, NULL) -- so by the time we get to ftdi_close() for the port which was unplugged, it _still_ oopses on dereferencing that NULL pointer, as it did before (and does in 2.6.29). The fix is just not to clear the private data in ftdi_sio_port_remove(). Then the refcount is properly reduced to zero when the final kref_put() happens in ftdi_close(). Remove a bogus comment too, while we're at it. And stop doing things inside "if (priv)" -- it must _always_ be there. Based loosely on an earlier patch by Daniel Mack, and suggestions by Alan Stern. Signed-off-by: David Woodhouse <> Tested-by: Daniel Mack <> Cc: Signed-off-by: Linus Torvalds <>
1 files changed, 1 insertions, 8 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 0ab8474b00cb..d9fcdaedf389 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1487,14 +1487,7 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)
- /* all open ports are closed at this point
- * (by usbserial.c:__serial_close, which calls ftdi_close)
- */
- if (priv) {
- usb_set_serial_port_data(port, NULL);
- kref_put(&priv->kref, ftdi_sio_priv_release);
- }
+ kref_put(&priv->kref, ftdi_sio_priv_release);
return 0;