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| author | Ian Abbott <abbotti@mev.co.uk> | 2006-06-26 11:44:22 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-07-12 16:03:22 -0700 |
| commit | 00d6058ac93048b525b86fa48b413dcb87ac2728 (patch) | |
| tree | 8d5eab6af613e8832ba182e54ec9d7f634517a26 /drivers/usb | |
| parent | 5650b4dd141e823c2b1bc248cb9ad3e9ac88cf19 (diff) | |
| download | linux-00d6058ac93048b525b86fa48b413dcb87ac2728.tar.gz linux-00d6058ac93048b525b86fa48b413dcb87ac2728.tar.bz2 linux-00d6058ac93048b525b86fa48b413dcb87ac2728.zip | |
[PATCH] USB serial visor: fix race in open/close
The anti user-DoS mechanism in the USB serial 'visor' driver can fail in
the following way:
visor_open: priv->outstanding_urbs = 0
visor_write: ++priv->outstanding_urbs
visor_close:
visor_open: priv->outstanding_urbs = 0
visor_write_bulk_callback: --priv->outstanding_urbs
So priv->outstanding_urbs ends up as (unsigned long)(-1). Not good!
I haven't seen this happen with the visor driver as I don't have the
hardware, but I have seen it while testing a patch to implement the same
functionality in the ftdi_sio driver (patch not yet submitted).
The fix is pretty simple: don't reinitialize outstanding_urbs in
visor_open. (Again, I haven't tested the fix in visor, but I have
tested it in ftdi_sio.)
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/visor.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c index cbc21465f4fb..32c3c6288985 100644 --- a/drivers/usb/serial/visor.c +++ b/drivers/usb/serial/visor.c @@ -302,7 +302,6 @@ static int visor_open (struct usb_serial_port *port, struct file *filp) spin_lock_irqsave(&priv->lock, flags); priv->bytes_in = 0; priv->bytes_out = 0; - priv->outstanding_urbs = 0; priv->throttled = 0; spin_unlock_irqrestore(&priv->lock, flags); |