diff options
| author | David Woodhouse <dwmw2@infradead.org> | 2009-05-18 14:07:35 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-18 17:37:15 +0200 |
| commit | 80193195f87ebca6d7417516d6edeb3969631c15 (patch) | |
| tree | 870be37dde8e7d2524c2cce5a4571d5a41f0a80a /drivers/usb | |
| parent | mtd_dataflash: unbreak erase support (diff) | |
| download | linux-80193195f87ebca6d7417516d6edeb3969631c15.tar.xz linux-80193195f87ebca6d7417516d6edeb3969631c15.zip | |
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 <David.Woodhouse@intel.com>
Tested-by: Daniel Mack <daniel@caiaq.de>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/usb')
| -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 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) 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; } |