diff options
| author | David Woodhouse <dwmw2@infradead.org> | 2009-05-18 13:07:35 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-06-15 09:39:58 -0700 |
| commit | 923811b7bd5e6dbc21a384147367e682e698eeda (patch) | |
| tree | a8ca867513bb5388b80821570336669c73fd8176 /drivers | |
| parent | 7b30cf45c0eaad6a87cf387a39a3638ebbced0fb (diff) | |
Fix oops on close of hot-unplugged FTDI serial converter
commit 80193195f87ebca6d7417516d6edeb3969631c15 upstream.
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 <David.Woodhouse@intel.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 5daa51703d5a..4423875b0016 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -1485,14 +1485,7 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port) remove_sysfs_attrs(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; } |